Allied Telesis EPSR AT-8948 User's Manual
Contents
1. Oya ees Enabled UFU Ment Links Up Control Vran i922 vlan1000 1000 Data VLAN S ii RR vlan2 2 First POPE dz eR Ie USES 1 First Port Status Forwarding First Port Direction Upstream Second Port scale 2 Second Port Status Forwarding Second Port Direction Downstream Mr ET Enabled Master Node 00 00 c 28 06 19 Page 32 AlliedWare OS How To Note EPSR EPSR State and Settings Master Node In contrast the following diagram shows the output for a master node in a ring that is in a in a Failed Ring Failed state Both ring ports are now forwarding EPSR Information Name x uo ou eden PG domainl tigi ne dep owe baa us Master Stat s eR Educa eae eae Enabled STATE uos Ev y te EG RIP eRS Failed Control Vian i22 1 1000 1000 Data VLBAN S ie km 9 wand vlan2 2 Primary Port uineas ie nr en 1 Primary Port Status Forwarding Secondary Port 2 Secondary Port Status Forwarding Hello Time eet ee he 1s Failover Time io2 93 3 s 2s Ring Flap Time piee 003 Os MAD Sob m Enabled Page 33 AlliedWare OS How To Note EPSR SNMP Traps SNMP Traps You can use SNMP traps to notify you when events occur in the EPSR ring Download the latest v2. Allied Telesis AlliedWare OS How To Configure EPSR Ethernet Protection Switching Ring to Protect a Ring from Loops Introduction Putting a ring of Ethernet switches at the core of a network is a simple way to increase the network s resilience such a network is no longer susceptible to a single point of failure However the ring must be protected from Layer 2 loops Traditionally STP based technologies are used to protect rings but they are relatively slow to recover from link failure This can create problems for applications that have strict loss requirements such as voice and video traffic where the speed of recovery is highly significant This How To Note describes a fast alternative to STP Ethernet Protection Switching Ring EPSR EPSR enables rings to recover rapidly from link or node failures within as little as 50ms depending on port type and configuration This is much faster than STP at 30 seconds or even RSTP at 1 to 3 seconds What information will you find in this document This How To Note begins by describing EPSR in the following sections e EPSR Works on page 3 Establishing a Ring on page 4 Detecting a Fault on page 5 Recovering from a Fault on page 5 Restoring Normal Operation on page 7 Next it gives step by step configuration details and examples in the following sections e How To Configure EPSR on page 8 Example 1 A Basic Ring on page 11 Example
3. 1 Failover Time Remaining seconds 0 RingFlap Time Remaining seconds 0 Helio SequenCe wo aem kr e RUMOR 526 Data WLdHSuiiigceibaee ede Ru eoe 2 Page 27 AlliedWare OS How To Note EPSR Example 6 EPSR with an iMAP Configure the AT TN7100 iMAP as a Transit Node The following diagram shows a partial script for the iMAP with the commands for configuring it as a transit node CREATE EPSR test TRANSIT CREATE VLAN vlan2 VID 2 FORWARDINGMODE STD CREATE VLAN vlan1000 VID 1000 FORWARDINGMODE STD DISABLE INTERFACE 0 0 0 15 1 0 1 15 2 0 2 15 4 0 4 1 5 0 5 1 ADD VLAN 2 INTERFACE ETH 5 0 1 FRAME TAGGED ADD VLAN 1000 INTERFACE ETH 5 0 1 FRAME TAGGED DELETE VLAN 1 INTERFACE ETH 5 0 1 SET INTERFACE 0 0 0 15 1 0 1 15 2 0 2 15 4 0 4 1 5 0 5 1 PROFILE AutoProv SET INTERFACE ETH 5 0 1 ACCEPTABLE VLAN DD EPSR test INTERFACE ETH 5 0 1 DD EPSR test VLAN 1000 TYPE CONTROL DD EPSR test VLAN 2 TYPE DATA DD D NABLE EPSR test p ENABLE INTERFACE 0 0 0 15 1 0 1 15 2 0 2 15 4 0 4 1 5 0 5 1 Checking the Transit Node Configuration To see a summary use the command show epsr The following diagram shows the expected output EPSR Domain Information EPSR Domain Node Ty
4. This example is the same as Example 1 A Basic Ring on page except that one of the three switches is an iMAP We used an AT TN7100 iMAP running 6 1 10 The ring ports on the iMAP are 5 0 and 5 1 The example first shows the configuration script for the iMAP as the master node then as the transit node For the configuration of the other two switches see Example 1 Configure the AT TN7100 iMAP as Master Node The following diagram shows a partial script for the IMAP with the commands for configuring it as a EPSR master node and other relevant commands ADD IP INTERFACE MGMT IPADDRESS 172 28 9 3 SUBNETMASK 255 255 255 0 CARD ACTCFC GATEWAY 172 28 9 1 SET SWITCH AGEINGTIMER 3 00 ET SYSTEM PROVMODE AUTO ET SYSTEM GATEWAY 172 28 9 1 REATE EPSR test MASTER HELLOTIME 1 FAILOVERTIME 2 RINGFLAPTIME 0 REATE VLAN vlan2 VID 2 FORWARDINGMODE STD REATE VLAN vlan1000 VID 1000 FORWARDINGMODE STD DD VLAN 2 INTERFACE ETH 5 0 1 FRAME TAGGED DD VLAN 1000 INTERFACE ETH 5 0 1 FRAME TAGGED D D O U DELETE VLAN 1 INTERFACE ETH 5 0 1 SET INTERFACE ETH 5 0 1 ACCEPTABLE VLAN D EPSR test INTERFACE ETH 5 0 TYPE PRIMARY D EPSR test INTERFACE ETH 5 1 TYPE SECONDARY D EPSR test VLAN 1000 TYPE CONTROL D EPSR test VLAN 2 TYPE DATA ENABLE EPSR test Page 26 AlliedWar
5. enable epsr domainl Configure EPSR for domain 2 This switch is a transit node create epsr domain2 mode transit controlvlan vlan40 add epsr domain2 datavlan vlan50 enable epsr domain2 Page 16 AlliedWare OS How To Note EPSR Example 3 EPSR and RSTP Example 3 EPSR and RSTP This example uses EPSR to protect one ring and RSTP to protect another overlapping ring Master RSTP Node Switch A port 1 part do C primary port 2 port 11 secondary port 1 port 10 Domain 1 RSTP control VLAN 1000 STP VLAN 10 data VLAN 2 port 2 port 11 Switch port 1 E port 10 port 2 port 11 Transit RSTP Node Switch B D epsr example rstp 1 Configure the master node switch A for the EPSR domain The master node is the same as in the previous example create vlan vlan1000 vid 1000 add vlan 1000 port 1 2 frame tagged create vlan vlan2 vid 2 add vlan 2 port 1 2 frame tagged delete vlan 1 port 1 2 create epsr domainl mode master controlvlan vlani1000 primaryport 1 add epsr domain1 datavlan vlan2 enable epsr domainl Page 17 AlliedWare OS How To Note EPSR Example 3 EPSR and RSTP 2 Configure the transit node switch B that belongs just to the EPSR domain This transit node B is the same as in the previous example create vlan vlan1000 vid 1000 add vlan 1000 port 1 2 frame tagged create vlan vlan2 vid 2 add vlan 2 port 1 2 frame tagged delete
6. AlliedWare OS How To Note EPSR Counters Counters The EPSR counters record the number of EPSR messages that the CPU received and transmitted To display the counters use the command show epsr domainl count Master node in following diagram shows the counters for a master node in a ring that has never had a a Complete link or node fail ring EPSR Counters Name 1 1 Receive Transmit Total EPSR Packets 1093 Total EPSR Packets 1093 Health 1092 Health 1092 Ring Up 1 Ring Up 1 Ring Down 0 Ring Down 0 Link Down 0 Link Down 0 Invalid EPSR Packets 0 Note that the node has generated 1093 EPSR packets and sent them out its primary port and has received the same number of EPSR packets on its secondary port However it is very common to see a few Link Down Ring Down and Ring Up entries in the output of a ring that has never been in a Failed state These messages are produced when you first enable EPSR if some ring nodes establish before others Transit Node contrast the following diagram shows the counters for a transit node in a ring that has ina ring that been in a Failed state twice had failures EPSR Counters Name 1 1 Receive Transmit Total EPSR Packets 1425 Total EPSR Packets 2 Health 1423 Health 0 Ring Up 2 Ring Up 0 Ring Down 0 Ring Down 0 Link Down 0 Link Down 2 Invalid EPSR Packets 0 Here the transit node has
7. Example 4 EPSR with Nested VLANs Example 4 EPSR with Nested VLANs In this example dient switches A and C are in the same end user VLAN vlan20 dient switches B and D are in the same end user VLAN vlan200 traffic for vlan20 and vlan200 is nested inside vlan50 for transmission around the core vlan5O is the data VLAN for the EPSR domain vlan100 is the control VLAN for the EPSR domain Client Client Switch Switch E H port 20 port 10 port 22 port 22 port 2 secondary porta Master Transit porti port Node Node primary A D EPSR Domain control VLAN 100 data VLAN 50 Transit Transit poti Node porti B C port 2 port 2 port 22 port 22 port 10 port 20 Client Client Switch Switch F epsr example nested Page 20 AlliedWare OS How To Note EPSR Example 4 EPSR with Nested VLANs l Configure the master node switch A for the EPSR domain Configure the EPSR control VLAN create vlan vlan100 vid 100 add vlan 100 port 1 2 frame tagged Configure vlan50 This VLAN acts as both the nested VLAN and the EPSR data VLAN The following commands create vlan50 and configure it as a nested VLAN create vlan vlan50 vid 50 nested add vlan 50 port 22 nestedtype customer add vlan 50 port 1 2 nestedtype core Remove the ring ports from the default VLAN delete vlan 1 port 1 2 Configure EPSR create epsr example mode master controlvlan vlani100 primarypo
8. 01000000 EPSR Portl Rx TYPE RING UP FLUSH FDB STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME O0 HELLO SEQ 0 Unblock EPSR test port 2 VLAN 2 Flush FDB EPSR test vid 2 EPSR INFO Send trap EPSR test oldState PRE FORWARDING newState LINK UP nodeType TRANSIT EPSR test oldState PRE FORWARDING newState LINK UP 9 The transit node receives Health messages The transit node continues receiving Health messages for as long as the ring stays in a state of Complete This is the packet shown in step 10 on page 52 of the master node debug output Manager 9924 B gt EPSR Porti Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541e71 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 01000177 EPSR Porti Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 375 USA Headquarters 19800 North Creek Parkway Suite 200 Bothell WA 98011 USA 1 800 424 4284 1 425 481 3895 European Headquarters Via Motta 24 6830 Chiasso Switzerland 41 91 69769 00 41 91 69769 11 Asia Pacific Headquarters Tai Seng Link Singapore 534182 65 6383 3832 65 6383 3830 www alliedtelesis com 2007 Allied Telesis Inc All rights reserved Information in this document is subject to
9. 1 port 4 5 Configure EPSR create epsr domain2 mode master controlvlan vlan40 primaryport 4 add epsr domain2 datavlan vlan50 enable epsr domain2 4 Configure the transit node switch D that belongs just to domain 2 Configure the control VLAN create vlan vlan40 vid 40 add vlan 40 port 4 5 frame tagged Configure the data VLAN create vlan vlan50 vid 50 add vlan 50 port 4 5 frame tagged Remove the ring ports from the default VLAN delete vlan 1 port 4 5 Page 15 AlliedWare OS How To Note EPSR Example 2 A Double Ring Configure EPSR create epsr domain2 mode transit controlvlan vlan40 add epsr domain2 datavlan vlan50 enable epsr domain2 5 Configure the transit node switch E that belongs to both domains Two separate EPSR domains are configured on this switch Configure the control VLAN for domain 1 create vlan vlan1000 vid 1000 add vlan 1000 port 1 2 frame tagged Configure the control VLAN for domain 2 create vlan vlan40 vid 40 add vlan 40 port 4 5 frame tagged Configure the data VLAN for domain 1 create vlan vlan2 vid 2 add vlan 2 port 1 2 frame tagged Configure the data VLAN for domain 2 create vlan vlan50 vid 50 add vlan 50 port 4 5 frame tagged Remove the ring ports from the default VLAN delete vlan 1 port 1 2 4 5 Configure EPSR for domain 1 This switch is a transit node create epsr domainl mode transit controlvlan vlan1000 add epsr domainl datavlan vlan2
10. EPSR will create a loop so is not recommended on a network with live data Of course in a live network you can manually prevent a loop by disconnecting the cable between any two of the nodes Page 10 AlliedWare OS How To Note EPSR Example 1 A Basic Ring Example 1 A Basic Ring This example builds a simple 3 switch ring with one data VLAN as shown in the following diagram Control packets are transmitted around the ring on vlan1000 and data packets on vlan2 End User Ports port 1 primary 2 port 2 secondary Master Node port 1 port 1 End User Ports End User Ports port 2 ring port 2 ring Transit Transit Node Node C B epsr example basic ring Configure the Master Node A 1 Create the control VLAN create vlan vlan1000 vid 1000 2 Add the ring ports to the control VLAN add vlan 1000 port 1 2 frame tagged 3 Create the data VLAN create vlan vlan2 vid 2 4 Add the ring ports to the data VLAN The two ring ports must belong to the control VLAN and all data VLANs add vlan 2 port 1 2 frame tagged Page 11 AlliedWare OS How To Note EPSR Example 1 A Basic Ring 5 Remove the ring ports from the default VLAN delete vlan 1 port 1 2 6 Create the EPSR domain This step creates the domain specifying that this switch is the master node It also specifies which VLAN is the control VLAN and which port is the primary port create
11. VLAN This is because the master node never forwards any EPSR messages that it receives The following diagram shows a basic ring with all the switches in the ring up End User Ports Control VLAN is forwarding Data VLAN is forwarding Master Node Transit Transit Node Node 1 End User Ports Transit Transit Node Node 2 End User Ports Control VLAN Primary Port P Data VLAN 1 Data VLAN 1 Secondary Port 5 Data VLAN_2 Data VLAN_2 epsr basic ring EPSR Components EPSR domain A protection scheme for an Ethernet ring that consists of one or more data VLANs and a control VLAN Master node The controlling node for a domain responsible for polling the ring state collecting error messages and controlling the flow of traffic in the domain Transit node Other nodes in the domain Ring port A port that connects the node to the ring On the master node each ring port is either the primary port or the secondary port On transit nodes ring ports do not have roles Primary port A ring port on the master node This port determines the direction of the traffic flow and is always operational Secondary port A second ring port on the master node This port remains active but blocks all protected VLANs from operating unless the ring fails Similar to the blocking port in an STP RSTP instance Control VLAN The VLAN over which all control messages
12. for matching on incoming packets EPSR creates a hardware filter that uses 2 bytes for VLAN identification since version 291 04 This means that you have to design your network carefully when using EPSR with DHCP snooping QoS or other hardware filters For example DHCP snooping uses 5 bytes to match on the source and destination UDP ports and the protocol field With EPSR and DHCP snooping both enabled 7 out of the 16 bytes are used IP addresses use 4 bytes So if you configured EPSR DHCP snooping and a QoS policy that classified on source IP address then 11 of the 16 bytes would be used Page 29 Allied Ware OS How To Note EPSR Ports and Recovery Times Ports and Recovery Times In practice recovery time in an EPSR ring is generally between 50 and 100ms However it depends on the port type because this determines how long it takes for the port to report that it is down and send a Link Down message The following ports report that they are down immediately or within a few milliseconds which leads to an EPSR recovery time of 50 to 100 ms 10 100 copper RJ 45 ports tri speed copper RJ 45 ports operating at 10 or 100M fiber 1000M ports 10G ports However for tri speed copper RJ 45 ports operating at 1000M there is a short delay either 350ms or 750ms before the port reports that it is down This is because the IEEE standard for 1000BASE T specifies that a port must wait for a certai
13. increments the Hello Sequence number with each message If all nodes and links in the ring are intact these Health messages are the only debugging output you see Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00060100 00541eef 00000000 0000 28 0619990b 00400105 03680000 00000000 cd280619 00010002 010000f9 EPSR Porti Tx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 249 EPSR Port2 Rx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00000100 00541eef 00000000 0000 28 0619990b 00400105 03680000 00000000 280619 00010002 010000f9 EPSR Port2 Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 249 3 The primary port goes down The link between the master node s primary port and the neighbouring transit node goes down Therefore the master node detects that its primary port port 1 has gone down EPSR test Port 1 port down Flush FDB EPSR test vid 2 Page 37 AlliedWare OS How To Note EPSR Debugging 4 The master node receives a Link Down message on its secondary port The master node receives a Link Down message on its secondary port port 2 from transit node B which is at t
14. port up EPSR INFO Send trap EPSR test oldState LINK DOWN newState PRE FORWARDING nodeType TRANSIT EPSR test oldState LINK DOWN newState PRE FORWARDING 7 The transit node receives another Health message The transit node receives another Health message This message will make it back to the master node s secondary port because the link between the two transit nodes is now up This is the packet shown in step 7 on page 50 of the master node debug output Manager 9924 B gt EPSR Portl Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541872 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 02000176 EPSR Porti Rx TYPE HEALTH STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 374 Page 55 AlliedWare OS How To Note EPSR 8 The transit node receives a Ring Up Flush FDB message The transit node receives a Ring Up Flush FDB message which indicates that the master node knows that all links in the ring are up again The transit node unblocks port 2 for vlan2 flushes its FDB sends a trap and changes state to Link Up This is the packet shown in step 8 on page 51 of the master node debug output EPSR Porti Rx 00e02500 00040000 280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541fea 00000000 0000ca28 0619990b 00400106 03e80000 00000000 cd280619 00000000
15. ring ports to the control VLAN Use the commands create vlan stack vid 1000 add vlan 1000 port 1 0 1 1 0 2 frame tagged delete vlan 1 port 1 0 1 1 0 2 Add the stacking VLAN to the stack and enable stacking add stack interface vlan1000 enable stack 2 Configure stacking on the first transit node host2 These commands must be entered into the CLI of this particular switch set system hostid 2 serialnumber 23456789 set system name host2 create vlan stack vid 1000 add vlan 1000 port 2 0 1 2 0 2 frame tagged delete vlan 1 port 2 0 1 2 0 2 add stack interface vlan1000 enable stack 3 Configure stacking on the second transit node host3 These commands must be entered into the CLI of this particular switch set system hostid 3 serialnumber 34567890 set system name host3 create vlan stack vid 1000 add vlan 1000 port 3 0 1 3 0 2 frame tagged delete vlan 1 port 3 0 1 3 0 2 add stack interface vlan1000 enable stack Page 24 AlliedWare OS How To Note EPSR Example 5 EPSR with management stacking 4 Configure the other VLANs on the stacked switches The stack now exists so you can configure all three switches from the CLI of the master node or any other of the switches However the ports and IP addresses are different for each switch so you need to make most of the commands host directed Create the EPSR data VLAN This command will propagate to all three switches create vlan vla
16. vid 2 EPSR INFO Send trap EPSR test oldState COMPLETE newState FAILED nodeType MASTER EPSR test oldState COMPLETE newState FAILED Page 38 AlliedWare OS How To Note EPSR Debugging 6 The Hello timer expires The Hello timer expires which would normally trigger the master node to send a Health message out the primary port However the link between the primary port and the neighbouring transit node is down so the master node does not send the Health message Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired 7 The primary port comes back up The primary port comes back up The master node immediately blocks that port for vlan2 to prevent a loop Manager x900 48 A gt EPSR test Port 1 port up Block EPSR test port 1 VLAN 2 8 The Hello timer expires again The Hello timer expires again Port 1 is now up so this time the master node sends a Health message The Health message shows that the EPSR state is Failed Note that the hello sequence number increments from the number it was before the primary port went down because the master node could not transmit Health messages while the port was down Manager x900 48 A gt epsrHe
17. 0 control VLAN 40 data VLAN 2 data VLAN 50 port 2 port 5 Transit port 1 Node port 4 E port 2 port 5 Transit Transit Node Node B D epsr example double ring 1 Configure the master node switch A for domain 1 The master node for domain 1 is the same as in the previous example except that the domain has been renamed create vlan vlan1000 vid 1000 add vlan 1000 port 1 2 frame tagged create vlan vlan2 vid 2 add vlan 2 port 1 2 frame tagged delete vlan 1 port 1 2 create epsr domainl mode master controlvlan vlan1000 primaryport 1 add epsr domainl datavlan vlan2 enable epsr domainl Page 14 AlliedWare OS How To Note EPSR Example 2 A Double Ring 2 Configure the transit node switch B that belongs just to domain 1 This transit node is the same as in the previous example except that the domain has been renamed create vlan vlan1000 vid 1000 add vlan 1000 port 1 2 frame tagged create vlan vlan2 vid 2 add vlan 2 port 1 2 frame tagged delete vlan 1 port 1 2 create epsr domainl mode transit controlvlan vlan1000 add epsr domainl datavlan vlan2 enable epsr domainl 3 Configure the master node switch C for domain 2 Configure the control VLAN create vlan vlan40 vid 40 add vlan 40 port 4 5 frame tagged Configure the data VLAN create vlan vlan50 vid 50 add vlan 50 port 4 5 frame tagged Remove the ring ports from the default VLAN delete vlan
18. 02 010000fb EPSR Porti Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME T FAIL TIME 2 HELLO SEQ 251 Manager 9924 B gt EPSR Port1 Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541eec 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 010000fc EPSR Porti Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 252 Page 46 AlliedWare OS How To Note EPSR Debugging Link Down Between Two Transit Nodes This section shows the debugging output when the link between transit node B and transit node C goes down and comes back up again It shows the debugging output for the complete failure and recovery cycle e onthe master node and then on transit node B Master Node Node A Debug Output The following debugging output starts with the ring established and in a state of Complete 1 The master node sends Health messages Each time the Hello timer expires the master node sends a Health message out its primary port port 1 As long as the ring is in a state of Complete it receives each Health message again on its secondary port port 2 Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 280619 8100e3e8 005caaaa 0300602b 00bb0100 00541
19. 06199906 00400105 03680000 00000000 cd280619 00010002 010000fb EPSR Porti Tx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 251 EPSR Port2 Rx 00e02b00 00040000 280619 8100e3e8 005caaaa 0300e02b 00060100 00541eed 00000000 0000 28 0619990b 00400105 03680000 00000000 280619 00010002 010000fb EPSR Port2 Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 251 Page 41 AlliedWare OS How To Note EPSR Debugging Transit Node Node B Debug Output The following debugging shows the same events as the previous section but on the transit node instead of the master node It starts with the ring established and in a state of Complete l The transit node receives Health messages The transit node receives Health messages on port 1 because that port is connected to the master node s primary port Note that in the System field this output shows the MAC address of the source of the message the master node in this case This is the packet shown in step on page 36 of the master node debug output EPSR Portl Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541f2a 00000000 0000 28 0619990b 00400105 03680000 00000000 280619 00010002 010000be EPSR Porti Rx T
20. 1 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 01000147 EPSR Portl Tx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 327 EPSR Port2 Rx 00e02500 00040000 280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541 1 00000000 0000ca28 0619990b 00400105 03e80000 00000000 cd280619 00010002 01000147 EPSR Port2 Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 327 Page 47 AlliedWare OS How To Note EPSR Debugging 2 The link between the two transit nodes goes down When the link goes down the master node transmits a Health message but does not receive it on its secondary port Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541ea0 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 01000148 EPSR Porti Tx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 328 3 The master node receives a Link Down message on its secondary port The master node receives a Link Down message which tells it that a link in the ring is broken This message came from the transit node on on
21. 2 A Double Ring on page 14 C613 16092 00 REV D www alliedtelesis com Which products and software versions does it apply to Example 3 EPSR and RSTP on page 17 Example 4 EPSR with Nested VLANs on page 20 Example 5 EPSR with management stacking on page 23 Example 6 EPSR with an iMAP on page 26 Next it discusses important implementation details in the following sections Classifiers and Hardware Filters on page 29 Ports and Recovery Times on page 30 e IGMP Snooping and Recovery Times on page 31 Health Message Priority on page 31 Finally it ends with troubleshooting information in the following sections State and Settings on page 32 e SNMP Traps on page 34 Counters on page 35 Debugging on page 36 Which products and software versions does it apply to This How To Note applies to the following Allied Telesis switches A AT 8948 x900 48FE x900 48FE N AT 9924T AT 9924SP and AT 9924T 4SP switches running software version 2 8 1 or later AT 9924Ts x900 24XT and x900 24XT N switches running software version 3 1 1 or later EPSR is also available on the following Allied Telesis switches running the Allied Ware Plus OS software version 5 2 1 or later SwitchBlade x908 x900 series For information about using the Allied Ware Plus OS see the Allied Ware Plus Note How To Configure EPSR Ethernet Protection Switching Ring to Protect a Ring f
22. 500 00040000 cd24024f 8100e3e8 005caaaa 0300 020 006060100 00542484 00000000 0000 24 024 990b 00400108 03e80000 00000000 cd24024f 00000000 04000000 EPSR Portl Tx TYPE LINK DOWN STATE LINK DOWN CTRL VLAN 1000 SYSTEM 00 00 cd 24 02 4f HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 EPSR INFO Send trap EPSR test oldState LINK UP newState LINK DOWN nodeType TRANSIT EPSR test oldState LINK UP newState LINK DOWN Page 54 AlliedWare OS How To Note EPSR Debugging 5 The transit node receives Health messages The transit node receives Health messages from the master node These have a state of Failed which shows that the ring is still broken This is the packet shown in step 6 on page 50 of the master node debug output Manager 9924 B gt EPSR Portl Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541d9f 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 02000149 EPSR Porti Rx TYPE HEALTH STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 329 6 The link comes back up The transit node detects that the broken link has come back up It blocks the port to prevent a loop from occurring sends a trap and changes the EPSR state to Pre forwarding Manager 9924 B gt Block EPSR test port 2 VLAN 2 EPSR test Port 2
23. 6 03680000 00000000 280619 00000000 01000000 EPSR Portl Tx TYPE RING UP FLUSH FDB STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Flush FDB EPSR test vid 2 EPSR INFO Send trap EPSR test oldState FAILED newState COMPLETE nodeType MASTER EPSR test oldState FAILED newState COMPLETE Il The master node receives the Ring Up Flush FDB message on port 2 The master node receives the Ring Up Flush FDB message back on its secondary port because the packet traversed the whole ring The master node ignores the message EPSR Port2 Rx 00e02b00 00040000 280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541fea 00000000 0000 28 0619990b 00400106 03680000 00000000 280619 00000000 01000000 EPSR Port2 Rx TYPE RING UP FLUSH FDB STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Page 40 AlliedWare OS How To Note EPSR Debugging 12 The master node transmits and receives Health messages The master node continues transmitting and receiving Health messages for as long as the ring stays in a state of Complete Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300602b 00bb0100 00541eed 00000000 0000 28
24. Note EPSR Master Node in a Complete Ring Transit Node in a Complete Ring EPSR State and Settings EPSR State and Settings To display the EPSR state the attached VLANs the ring ports and the timer values use the command show epsr The following diagram shows the output for a master node in a ring that is in a state of Complete As well as giving the state as Complete it also shows that port 1 is the primary port and port 2 is the secondary port Note that the secondary port is blocked so does not forward packets over the data VLAN vlan2 EPSR Information NaMe EU RUNDE test Mode 29x44 e EE EN E Master Stat sS 2 anno suras eei Web tS Eee Enabled State vaa vo MIR a eae Complete Control Vlar gabisa eiai edes vlan1000 1000 Data VLAN S 4i ERES a vlan2 2 Primary Poft 2 145 RT 1 Primary Port Status Forwarding Secondary iame iritisa Eas 2 Secondary Port Status Blocked Hello TIME soia ee bU RE E ERU dcs Failover Time i x s 2s Ring Flap Time 2 2 2 acess ex Os Enabled The following diagram shows the output for a transit node in a ring that is in a state of Complete Note that the State is Links Up not Complete Only the master node shows Complete as the state EPSR Information NAME fies es brew Ru ke uo RR XR RS test ModS Transit
25. PSR test port 1 VLAN 2 EPSR Port2 Tx 00e02500 00040000 cd24024f 8100e3e8 005caaaa 0300e02b 00060100 00542484 00000000 0000ca24 024f990b 00400108 03680000 00000000 cd24024f 00000000 04000000 EPSR Port2 Tx TYPE LINK DOWN STATE LINK DOWN CTRL VLAN 1000 SYSTEM 00 00 cd 24 02 4f HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 EPSR INFO Send trap EPSR test oldState LINK UP newState LINK DOWN nodeType TRANSIT EPSR test oldState LINK UP newState LINK DOWN 3 The transit node receives a Ring Down Flush FDB message In response to the Link Down message the master node sends a Ring Down Flush FDB message However this transit node does not need to flush its database it already did This is the packet shown in step 5 on page 38 of the master node debug output EPSR Port2 Rx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541ee9 00000000 0000 28 0619990b 00400107 03680000 00000000 cd280619 00000000 02000000 EPSR Port2 Rx TYPE RING DOWN FLUSH FDB STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Page 43 AlliedWare OS How To Note EPSR Debugging 4 Port 1 comes back up The transit node detects that port 1 has come back up It sends a trap and changes the EPSR state to Pre forwarding Note that it leaves port 1 blocked for vlan2 t
26. TYPE RING DOWN FLUSH FDB STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Unblock EPSR test port 2 VLAN 2 Flush FDB EPSR test vid 2 EPSR INFO Send trap EPSR test oldState COMPLETE newState FAILED nodeType MASTER EPSR test oldState COMPLETE newState FAILED 5 The master node receives a second Link Down message The master node receives a Link Down message from the transit node on the other side of the broken link This message arrived after a delay because the ring ports are 1000M ports see Ports and Recovery Times on page 30 The master node does not take any action in response to this message because it already responded to the broken link Manager x900 48 A gt EPSR Portl Rx 00e02b00 00040000 cd24024f 8100e3e8 005caaaa 0300e02b 00bb0100 00542484 00000000 0000 24 024f 990b 00400108 03e80000 00000000 cd24024f 00000000 04000000 EPSR Porti Rx TYPE LINK DOWN STATE LINK DOWN CTRL VLAN 1000 SYSTEM 00 00 cd 24 02 4f HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Page 49 AlliedWare OS How To Note EPSR Debugging 6 The master node continues sending Health messages The master node continues sending Health messages out its primary port It does not receive any of these at the secondary port which tells it that the link is still down Manager x900 48 A gt epsrHe
27. YPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 190 Manager 9924 B gt EPSR Portl Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00060100 00541 29 00000000 0000cd28 0619990b 00400105 03e80000 00000000 cd280619 00010002 010000bf EPSR Porti Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 191 Manager 9924 B gt EPSR Portl Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541eef 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 010000 9 EPSR Porti Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 249 Page 42 AlliedWare OS How To Note EPSR Debugging 2 Port 1 on the transit node goes down The transit node detects that port 1 between the transit node and the master node has gone down The transit node flushes its forwarding database blocks port 1 for the data VLAN to prevent a loop from forming when the master node comes back up sends a Link Down message towards the master node sends a trap and changes the EPSR state to Link Down This is the packet shown in step 4 on page 38 of the master node debug output EPSR test Port 1 port down Flush FDB EPSR test vid 2 Block E
28. ansit node B Master Node Node A Debug Output The following debugging output starts with the ring established and in a state of Complete 1 The master node sends Health messages Each time the Hello timer expires the master node sends a Health message out its primary port port 1 As long as the ring is in a state of Complete it receives each Health message again on its secondary port port 2 Note that in the System field this output shows the MAC address of the source of the message the master node in this case Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300602b 00bb0100 00541f2a 00000000 0000 28 06199906 00400105 03680000 00000000 cd280619 00010002 010000be EPSR Portl Tx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 190 EPSR Port2 Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00000100 00541f2a 00000000 0000 28 0619990b 00400105 03680000 00000000 280619 00010002 010000be EPSR Port2 Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 190 Page 36 AlliedWare OS How To Note EPSR Debugging 2 The master node continues sending Health messages The master node continues sending Health messages and
29. ardware filter copies the packet to the CPU which increments the master node s Receive Health counter Because the master received the Health message on its secondary port it knows that all links and nodes in the ring are up When the master node receives the Health message back on its secondary port it resets the Failover timer If the Failover timer expires before the master node receives the Health message back it concludes that the ring must be broken Note that the master node does not send that particular Health message out again If it did the packet would be continuously flooded around the ring Instead the master node generates a new Health message when the Hello timer expires Page 4 Allied Ware OS How To Note EPSR Detecting a Fault EPSR uses a fault detection scheme that alerts the ring when a break occurs instead of using a spanning tree like calculation to determine the best path The ring then automatically heals itself by sending traffic over a protected reverse path EPSR uses the following two methods to detect when a transit node or a link goes down Master node polling fault detection To check the condition of the ring the master node regularly sends Health messages out its primary port as described in Establishing a Ring on page 4 Ifall links and nodes in the ring are up the messages arrive back at the master node on its secondary port This can be a relatively slow detection method b
30. are sent and received EPSR never blocks this VLAN Data VLAN A VLAN that needs to be protected from loops Each EPSR domain has one or more data VLANs Page 3 AlliedVWare OS How To Note EPSR How EPSR Works Establishing a Ring Once you have configured EPSR on the switches the following steps complete the EPSR ring 1 The master node creates an EPSR Health message and sends it out the primary port This increments the master node s Transmit Health counter in the show epsr count command 2 The first transit node receives the Health message on one of its two ring ports and using a hardware filter sends the message out its other ring port Note that transit nodes never generate Health messages only receive them and forward them with their switching hardware This does not increment the transit node s Transmit Health counter However it does increment the Transmit counter in the show switch port command The hardware filter also copies the Health message to the CPU This increments the transit node s Receive Health counter The CPU processes this message as required by the state machines but does not send the message anywhere because the switching hardware has already done this 3 The Health message continues around the rest of the transit nodes being copied to the CPU and forwarded in the switching hardware 4 The master node eventually receives the Health message on its secondary port The master node s h
31. change without notice Allied Telesis is a trademark or registered trademark of Allied Telesis Inc in the United States and other countries All company names logos and product designs that are trademarks or registered trademarks are the property of their respective owners C613 16092 00 REV D Connecting The World Allied Telesis
32. dary port for data VLAN traffic but not for the control VLAN 3 flushing its forwarding database for its two ring ports 4 sending a Ring Up Flush FDB message from its primary port to all transit nodes Transit Nodes with One Port Down As soon as the fault has been fixed the transit nodes on each side of the previously faulty link section detect that link connectivity has returned They change their ring port state from Links Down to Pre Forwarding and wait for the master node to send a Ring Up Flush FDB control message Once these transit nodes receive the Ring Up Flush FDB message they flush the forwarding databases for both their ring ports change the state of their ports from blocking to forwarding for the data VLAN which allows data to flow through their previously blocked ring ports The transit nodes do not start forwarding traffic on the previously down ports until after they receive the Ring Up Flush FDB message This makes sure the previously down transit node ports stay blocked until after the master node blocks its secondary port Otherwise the ring could form a loop because it had no blocked ports Transit Nodes with Both Ports Down The Allied Telesis implementation includes an extra feature to improve handling of double link failures If both ports on a transit node are down and one port comes up the node puts the port immediately into the forwarding state and starts forwarding data out that port It doe
33. dy have a ring in a live network disconnect the cable between any two of the nodes before you start configuring EPSR to prevent a loop 2 On each switch configure EPSR On each switch perform the following configuration steps Configuration of the master node and each transit node is very similar i Configure the control VLAN This step creates the control VLAN and adds the ring ports to it as tagged ports Enter the commands create vlan control vlan name vid control vid add vlan control vid port ring ports frame tagged Note that you can use trunk groups for the ring ports ii Configure the data VLAN This step creates the data VLAN or VLANs you can have as many as you want and adds the ring ports as tagged ports Enter the commands create vlan data vlan name vid data vid add vlan data vid port ring ports frame tagged The two ring ports must belong to the control VLAN and all data VLANs Page 8 AlliedVWare OS How To Note EPSR How To Configure EPSR Remove the ring ports from the default VLAN If you leave all the ring ports in the default VLAN vlan1 they will create a loop unless vian1 is part of the EPSR domain To avoid loops you need to do one of the following vlan1 data VLAN or remove the ring ports from vlan1 remove at least one of the ring ports from vlan1 on at least one of the switches We do not recommend this option because the action you have taken i
34. e OS How To Note EPSR Example 6 EPSR with an iMAP Checking the Master Node Configuration To see summary use the command show epsr The following diagram shows the expected output EPSR Domain Information EPSR Domain Node Type Domain Status Control Interface s PhysicalState State Vlan Type State test MASTER EN COMPLETE 1000 5 0 UP DNSTRM FWDING 5 1 UP DNSTRM BLOCKED To see details use the command show epsr test The following diagram shows the expected output EPSR Domain Information EPSR Domain Name leen test EPSR Domain Node Type Master EPSR Domain COMPLETE MAC Address of Master Node 00 00 CD 28 06 19 EPSR Domain Enabled Control WMlgmnilc oti ee eX ree gnus 1000 Primary Interface s 5 0 Physical State of Primary Interface UP Primary Interface Type DOWNSTREAM Primary Interface State FORWARDING Secondary Interface 5 1 Physical State of Secondary Interface UP Secondary Interface Type DOWNSTREAM Secondary Interface State BLOCKED Hello Timer seconds 1 Failover Timer seconds 2 RingFlap Timer seconds 0 Hello Time Remaining seconds
35. e side of the broken link EPSR Port2 Rx 00e02b00 00040000 20 101 8100e3e8 005caaaa 0300e02b 00bb0100 00544726 00000000 0000cd20 101990b 00400108 03e80000 00000000 cd20 101 00000000 04000000 EPSR Port2 Rx TYPE LINK DOWN STATE LINK DOWN CTRL VLAN 1000 SYSTEM 00 00 cd 20 f1 01 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Page 48 AlliedWare OS How To Note EPSR Debugging 4 The master node transmits a Ring Down Flush FDB message In response to the Link Down message the master node transmits a Ring Down Flush FDB message out both its primary and secondary ports The message has to go out both ports to make sure it reaches the nodes on both sides of the broken link The master node also unblocks its secondary port for vlan2 flushes its forwarding database sends a trap and changes the EPSR state to Failed EPSR Portl Tx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541ee9 00000000 0000ca28 0619990b 00400107 03e80000 00000000 cd280619 00000000 02000000 EPSR Porti Tx TYPE RING DOWN FLUSH FDB STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 EPSR Port2 Tx 00e02500 00040000 280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541ee9 00000000 0000ca28 0619990b 00400107 03e80000 00000000 cd280619 00000000 02000000 EPSR Port2 Tx
36. e time this takes by tuning the IGMP timers especially the queryresponseinterval parameter For more information see the IGMP Timers and Counters section of How To Configure IGMP on Allied Telesyn Routers and Switches for Multicasting This How To Note is available in the Resource Center of the Documentation and Tools CDROM for Software Version 2 8 1 or from www alliedtelesyn co uk en gb solutions techdocs asp area howto Query solicitation also works with networks that use Spanning Tree STP RSTP or MSTP Health Message Priority EPSR uses Health messages to check that the ring is intact If switches in the ring were to drop Health messages this could make the ring unstable Therefore Health messages are sent to the highest priority queue queue 7 which uses strict priority scheduling by default This makes sure that the switches forward Health messages even if the network is congested We recommend that you leave queue 7 as the highest priority queue leave it using strict priority scheduling and only send essential control traffic to it In the unlikely event that this is impossible you can increase the failover time so that the master node only changes the ring topology if several Health messages in a row fail to arrive By default the failover time is set to two seconds which means that the master node decides that the ring is down if two Health messages in a row fail to arrive Page 31 AlliedWare OS How To
37. ecause it depends on how often the node sends Health messages Note that the master node only ever sends Health messages out its primary port If its primary port goes down it does not send Health messages Transit node unsolicited fault detection To speed up fault detection EPSR transit nodes directly communicate when one of their interfaces goes down When a transit node detects a fault at one of its interfaces it immediately sends a Link Down message over the link that remains up This notifies the master node that the ring is broken and causes it to respond immediately Recovering from a Fault Fault in a link or a transit node When the master node detects an outage somewhere in the ring using either detection method it restores traffic flow by declaring the ring to be in a Failed state 2 unblocking its secondary port which enables data VLAN traffic to pass between its primary and secondary ports 3 flushing its own forwarding database FDB for the two ring ports How EPSR Works Master Node States Complete The state when there are no link or node failures on the ring Failed The state when there is a link or node failure on the ring This state indicates that the master node received a Link Down message or that the failover timer expired before the master node s secondary port received a Health message Transit Node States Idle The state when EPSR is first configured before
38. epsr test mode master controlvlan vlan1000 primaryport 1 7 Add the data VLAN to the domain add epsr test datavlan vlan2 8 Enable EPSR enable epsr test Configure the Transit Nodes B and C Each of the transit nodes has the same EPSR configuration in this example 1 Create the control VLAN create vlan vlan1000 vid 1000 2 Add the ring ports to the control VLAN add vlan 1000 port 1 2 frame tagged 3 Create the data VLAN create vlan vlan2 vid 2 4 Add the ring ports to the data VLAN The two ring ports must belong to both the control VLAN and all data VLANs add vlan 2 port 1 2 frame tagged 5 Remove the ring ports from the default VLAN delete vlan 1 port 1 2 Page 12 AlliedWare OS How To Note EPSR Example 1 A Basic Ring 6 Create the EPSR domain This step creates the domain specifying that this switch is the transit node It also specifies which VLAN is the control VLAN create epsr test mode transit controlvlan vlan1000 7 Add the data VLAN to the domain add epsr test datavlan vlan2 8 Enable EPSR enable epsr test Page 13 AlliedWare OS How To Note EPSR Example 2 A Double Ring Example 2 A Double Ring This example adds to the previous ring by making two domains as shown in the following diagram Master Master Node Node A port 1 port 4 C primary primary port 2 port 5 secondary secondary BeOS port 4 Domain 1 Domain 2 control VLAN 100
39. ersion of the Allied Telesis Enterprise MIB from www alliedtelesis co nz support updates patches html The EPSR Group is contained in the sub file called atr epsr mib The EPSR Group has the object identifier prefix epsr modules 136 and contains a collection of objects and traps for monitoring EPSR states The following trap is defined under the epsrEvents epsr 0 subtree atrEpsrNodeTrap epsrEvents 1 is the trap type of the EPSR node trap master transit The following objects are defined under the epsrEventVariables epsr 1 subtree atrEpsrNodeTrapType epsrEventVariables 1 is the trap type of the EPSR node trap master transit atrEpsrDomainName epsrEventVariables 2 is the name assigned to the EPSR domain atrEpsrFromState epsrEventVariables 3 is the defined state that an EPSR domain is transitioning from atrEpsrToState epsrEventVariables 4 is the state that an EPSR domain is transitioning to atrEpsrControlVLANld epsrEventVariables 5 is the VLAN identifier for the control VLAN atrEpsrPrimarylflndex epsrEventVariables 6 is the iflndex of the primary interface atrEpsrPrimarylfState epsrEventVariables 7 is the current state of the primary interface atrEpsrSecondarylflndex epsrEventVariables 8 is the iflndex of the secondary interface atrEpsrSecondarylfState epsrEventVariables 9 is the current state of the secondary interface Page 34
40. fore the master node realises that the ring is broken and acts accordingly As part of the recovery process the master node sends a Ring Down Flush FDB message The transit node receives this message and flushes its forwarding database This is the packet shown in step 4 on page 49 of the master node debug output EPSR Portl Rx 00e02b00 00040000 280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541ee9 00000000 0000ca28 0619990b 00400107 03e80000 00000000 cd280619 00000000 02000000 EPSR Porti Rx TYPE RING DOWN FLUSH FDB STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Flush FDB EPSR test vid 2 4 The transit node sends a Link Down message The transit node realises that its port is down sends a Link Down message sends a trap and changes its state to Link Down The transit node sends this message some time after the link actually went down because the ring ports are 1000M ports see Ports and Recovery Times on page 30 Note that by this stage the ring has already changed topology to restore traffic flow The master node detected the link failure by receiving a Link Down message from the other side of the link This is the Link Down message that the master switch received in step 5 on page 49 Manager 9924 B gt EPSR test Port 2 port down Flush FDB EPSR test vid 2 Block EPSR test port 2 VLAN 2 EPSR Porti Tx 00602
41. he other end of the broken link EPSR Port2 Rx 00e02b00 00040000 cd24024f 8100e3e8 005caaaa 0300e02b 00bb0100 00542484 00000000 0000cd24 024f990b 00400108 03680000 00000000 24024 00000000 04000000 EPSR Port2 Rx TYPE LINK DOWN STATE LINK DOWN CTRL VLAN 1000 SYSTEM 00 00 cd 24 02 4f HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 In the System field this output shows the MAC address of the source of the message the transit node in this case 5 The master node transmits a Ring Down Flush FDB message The master switch responds to the break in the ring by sending a Ring Down Flush FDB message which tells each transit node to learn the new topology The master node also unblocks its secondary port for the data VLAN vlan2 flushes its FDB sends an SNMP trap and changes the EPSR state to Failed Note that the master node sends the Ring Down Flush FDB message only out its secondary port because the link between the primary port and the neighbouring transit node is down EPSR Port2 Tx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541ee9 00000000 0000 28 0619990b 00400107 03680000 00000000 cd280619 00000000 02000000 EPSR Port2 Tx TYPE RING DOWN FLUSH FDB STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Unblock EPSR test port 2 VLAN 2 Flush FDB EPSR test
42. lloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 280619 8100e3e8 005caaaa 0300602b 00bb0100 00541dee 00000000 0000cd28 0619990b 00400105 03e80000 00000000 cd280619 00010002 020000fa EPSR Portl Tx TYPE HEALTH STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 250 Page 39 AlliedWare OS How To Note EPSR Debugging 9 The master node receives the Health message on its secondary port The master node receives the Health message on its secondary port port 2 This tells it that all links on the ring are up again EPSR Port2 Rx 00e02500 00040000 280619 8100e3e8 005caaaa 0300e02b 00060100 00541dee 00000000 0000cd28 0619990b 00400105 03680000 00000000 280619 00010002 020000fa EPSR Port2 Rx TYPE HEALTH STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 250 10 The master node returns the ring to a state of Complete The master node blocks its secondary port for the data VLAN unblocks its primary port transmits a Ring Up Flush FDB message flushes its FDB sends a trap and changes the EPSR state to Complete Block EPSR test port 2 VLAN 2 Unblock EPSR test port 1 VLAN 2 EPSR Porti Tx 00 02600 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541fea 00000000 0000 28 0619990b 0040010
43. lloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 006060100 00541d9f 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 02000149 EPSR Portl Tx TYPE HEALTH STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 329 7 The master node receives a Health message The master node transmits a Health message and receives it at the secondary port This indicates that the link is back up Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 280619 8100e3e8 005caaaa 0300602b 006060100 00541872 00000000 0000ca28 0619990b 00400105 03e80000 00000000 cd280619 00010002 02000176 EPSR Portl Tx TYPE HEALTH STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 374 EPSR Port2 Rx 00e02b00 00040000 280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541472 00000000 0000ca28 0619990b 00400105 03e80000 00000000 cd280619 00010002 02000176 EPSR Port2 Rx TYPE HEALTH STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 374 Page 50 AlliedWare OS How To Note EPSR Debugging 8 The master node returns the ring to a state of Complete No
44. mits and receives Health messages The master node continues transmitting and receiving Health messages for as long as the ring stays in a state of Complete Manager x900 48 A gt epsrHelloTimeout EPSR test Hello Timer expired EPSR Porti Tx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541e71 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 01000177 EPSR Porti Tx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 375 EPSR Port2 Rx 00e02500 00040000 280619 8100e3e8 005caaaa 0300e02b 00660100 00541e71 00000000 0000cd28 0619990b 00400105 03e80000 00000000 cd280619 00010002 01000177 EPSR Port2 Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 375 Page 52 AlliedWare OS How To Note EPSR Debugging Transit Node Node B Debug Output The following debugging shows the same events as the previous section but on the transit node instead of the master node It starts with the ring established and in a state of Complete 1 The transit node receives Health messages The transit node receives Health messages on port 1 because that port is connected to the master node s primary port Note that the message shows that the ring state is Complete This is the packet
45. n length of time after a link goes down before it decides that the link is actually down see Section 40 4 5 2 of IEEE Std 802 3 2002 The length of the wait depends on whether the 1000BASE T port is master or slave end of the link master and slave are determined when the port autonegotiates and are not related to the master node of EPSR If a 1000BASE T port is the master the wait is 750 ms if it is the slave the wait is 350ms This means that if a 1000M copper link goes down between two transit nodes EPSR recovers after approximately 350ms The EPSR nodes at both ends of the broken link send a Link Down message when they detect that the link has gone down As the diagram shows the node at the slave end of the link sends a Link Down message in 350ms The node at the master end does not send a Link Down message until 750ms have passed but by then the EPSR master node after 750ms has already handled the first Link Down message You can see the messages in the debugging output in Link Down Between Two Sm Transit Nodes on page 47 Master Node Link Down after 350ms slave end of link Transit Node master end of link For almost all networks this slight delay in recovery has no practical effect For networks with extremely stringent failover requirements we recommend using fiber 1000M ports instead of copper Page 30 AlliedWare OS How To Note EPSR IGMP Snooping and Rec
46. n20 vid 20 Assign ports and an IP address to the data VLAN on each switch You can type the following commands into any switch in the stack To apply them to the correct switches make them host directed by starting each command with the host ID number of the target switch Therefore use the following commands 1 add vlan 20 port 1 0 1 1 0 2 frame tagged add ip int vlan20 ip 192 168 20 1 add vlan 20 port 2 0 1 2 0 2 frame tagged add ip int vlan20 ip 192 168 20 2 add vlan 20 port 3 0 1 3 0 2 frame tagged w Ww N N e add ip int vlan20 ip 192 168 20 3 Configure other VLANSs as required In this example two of the switches have other VLANs attached 1 create vlan vlan45 vid 45 add vlan 45 port 1 0 23 1 0 24 frame tagged add ip int vlan45 ip 192 168 45 1 create vlan vlan30 vid 30 add vlan 30 port 2 0 10 frame tagged Oo FP add ip int vlan30 ip 192 168 30 1 Enable IP on the whole stack enable ip 5 Configure EPSR on the stacked switches Create the EPSR domain 1 create epsr example mode master controlvlan stack primary 1 0 1 2 create epsr example mode transit controlvlan stack 3 create epsr example mode transit controlvlan stack Specify the data VLAN add epsr example datavlan vlan20 Enable the EPSR domain enable epsr example Page 25 AlliedWare OS How To Note EPSR Example 6 EPSR with an iMAP Example 6 EPSR with an iMAP
47. nable ip add ip interface vlan200 ip 192 168 200 10 Page 22 AlliedWare OS How To Note EPSR Example 5 EPSR with management stacking Example 5 EPSR with management stacking In this example three switches are stacked together so you can manage all three switches by entering commands into the CLI of any one of them the three switches are also configured as an EPSR domain vlan1000 is used as the stacking VLAN and as the EPSR control VLAN Stacked switches use the stacking VLAN to communicate with each other the data VLAN for EPSR is vlan20 ports on the stacked switches are numbered using the stacking scheme of hostid O port vlan45 port 1 0 1 port 1 0 2 primary secondary Master Node host1 port 2 0 1 port 3 0 1 Transit Transit Node port 2 0 2 port 3 0 2 Node host2 host3 vlan30 epsrexample stack Page 23 AlliedWare OS How To Note EPSR Example 5 EPSR with management stacking 1 Configure stacking on the master node for the EPSR domain host The following commands must be entered into the CLI of this particular switch First give the switch a host ID number so that the stack can identify it set system hostid 1 serialnumber 12345678 set system name host1 Create the stacking VLAN and add the ring ports to it Note the port numbering notation these are ports 1 and 2 on stacking host 1 Because this VLAN will also be the EPSR control VLAN this step also adds the
48. ng Up Flush FDB message The Health message from the previous step reaches the master node and shows it that all links in the ring are now up The master node sends a Ring Up Flush FDB message When it receives the message the transit node unblocks port 1 for vlan2 flushes its FDB sends a trap and changes the state to Link Up This is the packet shown in step 10 on page 40 of the master node debug output EPSR Porti Rx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00000100 00541fea 00000000 0000 28 0619990b 00400106 03680000 00000000 280619 00000000 01000000 EPSR Porti Rx TYPE RING UP FLUSH FDB STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 Unblock EPSR test port 1 VLAN 2 Flush FDB EPSR test vid 2 EPSR INFO Send trap EPSR test oldState PRE FORWARDING newState LINK UP nodeType TRANSIT EPSR test oldState PRE FORWARDING newState LINK UP Page 45 AlliedWare OS How To Note EPSR Debugging 7 The transit node receives Health messages The transit node continues receiving Health messages for as long as the ring stays in a state of Complete This is the packet shown in step 12 on page 41 of the master node debug output Manager 9924 B gt EPSR Portl Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00060100 00541eed 00000000 0000 28 0619990b 00400105 03e80000 00000000 280619 000100
49. o make sure there are no loops Manager 9924 B gt Block EPSR test port 1 VLAN 2 EPSR test Port 1 port up EPSR INFO Send trap EPSR test oldState LINK DOWN newState PRE FORWARDING nodeType TRANSIT EPSR test oldState LINK DOWN newState PRE FORWARDING 5 Transit node receives a Health message Now that the master node s primary port is up again it sends a Health message Now that the transit node s port 1 is up again for the control VLAN the transit node receives the message This demonstrates that the transit node has only blocked port 1 for the data VLAN not the control VLAN EPSR control messages never loop because the master node never forwards them between its ring ports Note that the hello sequence number increments from the number it was before the primary port went down because the master node could not transmit Health messages while the port was down This is the packet shown in step 8 on page 39 of the master node debug output Manager 9924 B gt EPSR Portl Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00060100 00541dee 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 020000fa EPSR Porti Rx TYPE HEALTH STATE FAILED CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 250 Page 44 AlliedWare OS How To Note EPSR Debugging 6 Transit node receives a Ri
50. overy Times IGMP Snooping and Recovery Times Since Software Version 281 03 IGMP snooping includes query solicitation a new feature that minimises loss of multicast data after a topology change When IGMP snooping is enabled on a VLAN and EPSR changes the underlying link layer topology of that VLAN this can interrupt multicast data flow for a significant length of time Query solicitation prevents this by monitoring the VLAN for any topology changes When it detects a change it generates a special IGMP Leave message known as a Query Solicit and floods the Query Solicit message to all ports When the IGMP Querier receives the message it responds by sending a General Query This refreshes snooped group membership information in the network Query solicitation functions by default without you enabling it on the EPSR master node By default the master node always sends a Query Solicit message when the topology changes On other switches in the network the query solicitation is disabled by default but you can enable it by using the command set igmpsnooping vlan vlan name 1 4094 all querysolicit on yes true If you enable query solicitation on an EPSR transit node both that node and the master node send a Query Solicit message Once the Querier receives the Query Solicit message it sends out a General Query and waits for responses which update the snooping information throughout the network If necessary you can reduce th
51. pe Domain Status Control Interface s PhysicalState State Vlan Type State test TRANSIT EN LINKS UP 1000 5 0 UP UPSTRM FWDING 5 1 UP DNSTRM FWDING Page 28 AlliedWare OS How To Note EPSR To see details use the command show epsr test The following diagram shows the expected output Classifiers and Hardware Filters EPSR Domain EPSR Domain EPSR Domain MAC Address EPSR Domain Control Vlan Ring Interfa Physical Sta Ring Interfa Ring Interfa Ring Interfa Physical Sta Ring Interfa Ring Interfa Hello Timer Data Vlans ce db Wet ee teed ada beeen te of Ring Interface 1 1 ce 1 State aces Qe db ea deere amp te of Ring Interface 2 ce 2 Typer saipa e ege ce 2 State d SECONdS nubs hee eee Failover Timer seconds Ringflap Timer seconds Hello Time Remaining seconds Failover Time Remaining seconds Ringflap Time Remaining seconds Hello EPSR Domain Information test Transit LINKS UP 00 00 CD 24 02 4F Enabled 1000 UP UPSTREAM FORWARDING 5 1 DOWNSTREAM FORWARDING Classifiers and Hardware Filters On AT 8948 AT 9900 AT 9900s and x900 series switches the switching hardware has a limit of 16 bytes to use
52. received 1421 Health messages which it will have forwarded on if its ports were up These messages do not show in the transmit counters because they are transmitted by the switching hardware not the CPU The node has also generated two Link Down messages indicating that on two separate occasions one of its links has gone down Page 35 AlliedWare OS How To Note EPSR Debugging Debugging This section walks you through the EPSR debugging output as links go down and come back up again The debugging output comes from the ring in Example 1 A Basic Ring on page 11 The output shows what happened when we took down two separate links in turn first the link between the master node s primary port and transit node B second the link between the two transit nodes B and C To enable debugging on the domain called test use the command enable epsr test debug all Note that the master node transmits Health messages every second by default The debugging displays every message including all Health messages Therefore we recommend that you capture the debugging output for separate analysis to make analysis simpler Link Down Between Master Node and Transit Node This section shows the debugging output when the link between the master node s primary port and transit node B goes down and comes back up again It shows the debugging output for the complete failure and recovery cycle first on the master node then on tr
53. rom Loops This Note is available from www alliedtelesis com resources literature howto plus aspx The implementation on the above switches is also compatible with EPSR on Allied Telesis Multiservice Access Platforms iMAPs Page 2 Allied Ware OS How To Note EPSR Control VLAN is forwarding Data VLAN is blocked End User Ports How EPSR Works How EPSR Works EPSR operates on physical rings of switches note not on meshed networks When all nodes and links in the ring are up EPSR prevents a loop by blocking data transmission across one port When a node or link fails EPSR detects the failure rapidly and responds by unblocking the blocked port so that data can flow around the ring In EPSR each ring of switches forms an EPSR domain One of the domain s switches is the master node and the others are transit nodes Each node connects to the ring via two ports One or more data sends data around the ring and a control VLAN sends EPSR messages A physical ring can have more than one EPSR domain but each domain operates as a separate logical group of VLANs and has its own control VLAN and master node On the master node one port is the primary port and the other is the secondary port When all the nodes in the ring are up EPSR prevents loops by blocking the data VLAN on the secondary port The master node does not need to block any port on the control VLAN because loops never form on the control
54. rt 1 add epsr example datavlan vlan50 enable epsr example 2 Configure the transit nodes switches B C and D for the EPSR domain Each of the transit nodes has the same EPSR configuration in this example Configure the EPSR control VLAN create vlan vlan100 vid 100 add vlan 100 port 1 2 frame tagged Configure vlan50 which acts as both the nested VLAN and the EPSR data VLAN create vlan vlan50 vid 50 nested add vlan 50 port 22 nestedtype customer add vlan 50 port 1 2 nestedtype core Remove the ring ports from the default VLAN delete vlan 1 port 1 2 Configure EPSR create epsr example mode transit controlvlan vlan100 add epsr example datavlan vlan50 enable epsr example Page 21 AlliedWare OS How To Note EPSR Example 4 EPSR with Nested VLANs 3 Configure client switch E connected to the master node create vlan vlan20 vid 20 add vlan 20 port 20 frame tagged enable ip add ip interface vlan20 ip 192 168 20 10 4 Configure client switch F connected to transit node B create vlan vlan200 vid 200 add vlan 200 port 10 frame tagged enable ip add ip interface vlan200 ip 192 168 200 1 5 Configure client switch G connected to transit node C create vlan vlan20 vid 20 add vlan 20 port 20 frame tagged enable ip add ip int vlan20 ip 192 168 20 1 6 Configure client switch H connected to transit node D create vlan vlan200 vid 200 add vlan 200 port 10 frame tagged e
55. s less obvious when maintaining the network later In this How To Note we remove the ring ports from the default VLAN Use the command delete vlan 1 port ring ports iv Configure the EPSR domain This step creates the domain specifying whether the switch is the master node or a transit node It also specifies which VLAN is the control VLAN and on the master node which port is the primary port Enter one of the following commands On the master node create epsr name mode master controlvlan control vlan name primaryport port number On each transit node create epsr name mode transit controlvlan control vlan name This step also adds the data VLAN to the domain Enter the command add epsr name datavlan data vlan name v Enable EPSR This step enables the domain on each switch Enter the command enable epsr name 3 Configure other ports and protocols as required On each switch configure the other ports and protocols that are required for your network Page 9 Allied Ware OS How To Note EPSR How To Configure EPSR Modifying the Control VLAN You cannot modify the control VLAN while EPSR is enabled If you try to remove or add ports to the control VLAN the switch generates an error message as follows Manager delete vlan 1000 port 1 Error 3089409 VLAN 1000 is a control VLAN in EPSR and cannot be modified Disable the EPSR domain and then make the required changes Note that disabling
56. s not need to wait because the node knows there is no loop in the ring because the other ring port on the node is down 2 remains in the Links Down state 3 starts a DoubleFailRecovery timer with a timeout of four seconds 4 waits for the timer to expire At that time if one port is still up and one is still down the transit node sends a Ring Up Flush FDB message out the port that is up This message is usually called a Fake Ring Up message Sending this message allows any ports on other transit nodes that are blocking or in the Pre forwarding state to move to forwarding traffic in the Links Up state The timer delay lets the device at the other end of the link that came up configure its port appropriately so that it is ready to receive the transmitted message Note that the master node would not send a Ring Up Flush FDB message in these circumstances because the ring is not in a state of Complete The master node s secondary port remains unblocked Page 7 AlliedVWare OS How To Note EPSR How To Configure EPSR How To Configure EPSR This section first outlines step by step how to configure EPSR Then it discusses changing the settings for the control VLAN if you need to do this after initial configuration Configuring EPSR 1 Connect your switches into a ring EPSR does not in itself limit the number of nodes that can exist on any given ring Each switch can participate in up to 16 rings If you alrea
57. shown in step on page 47 of the master node debug output Manager 9924 B gt EPSR Porti Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541ea1 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 01000147 EPSR Porti Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 327 2 The link between the two transit nodes goes down The transit node receives Health message 328 At this stage the message does not indicate that anything is wrong However between messages 327 and 328 the link went down This means that message 328 will not make it back to the master node This is the packet shown in step 2 on page 48 of the master node debug output Manager 9924 B gt EPSR Porti Rx 00e02b00 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541ea0 00000000 0000 28 0619990b 00400105 03e80000 00000000 cd280619 00010002 01000148 EPSR Porti Rx TYPE HEALTH STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 1 FAIL TIME 2 HELLO SEQ 328 Page 53 AlliedWare OS How To Note EPSR Debugging 3 The transit node receives a Ring Down Flush FDB message In the meanwhile the master node has received a Link Down message from the switch at the other end of the broken link in step 3 on page 48 There
58. the master node determines that all links in the ring are up In this state both ports on the node are blocked for the data VLAN From this state the node can move to Links Up or Links Down Links Up The state when both the node s ring ports are up and forwarding From this state the node can move to Links Down Links Down The state when one or both of the node s ring ports are down From this state the node can move to Pre forwarding Pre forwarding The state when both ring ports are up but one has only just come up and is still blocked to prevent loops From this state the transit node can move to Links Up if the master node blocks its secondary port or to Links Down if another port goes down 4 sending an EPSR Ring Down Flush FDB control message to all the transit nodes via both its primary and secondary ports The transit nodes respond to the Ring Down Flush FDB message by flushing their forwarding databases for each of their ring ports As the data starts to flow in the ring s Page 5 Allied Ware OS How To Note EPSR How EPSR Works new configuration the nodes master and transit re learn their layer 2 addresses During this period the master node continues to send Health messages over the control VLAN This situation continues until the faulty link or node is repaired For a multidomain ring this process occurs separately for each domain within the ring The following figure shows the flo
59. vlan 1 port 1 2 create epsr domainl mode transit controlvlan vlan1000 add epsr domainil datavlan vlan2 enable epsr domainl 3 Configure the switches that belong to the RSTP instance switches C and D Switches C and D have the same configuration in this example Configure the STP VLAN create vlan vlan10 vid 10 add vlan 10 port 10 11 frame tagged Remove the STP VLAN s ports from the default VLAN delete vlan 1 port 10 11 Configure STP create stp exampl add stp example vlan vlan10 enable stp example set stp example mode rapid Page 18 AlliedWare OS How To Note EPSR Example 3 EPSR and RSTP 4 Configure switch E for EPSR and RSTP Configure the control VLAN for EPSR create vlan vlan1000 vid 1000 add vlan 1000 port 1 2 frame tagged Configure the data VLAN for EPSR create vlan vlan2 vid 2 add vlan 2 port 1 2 frame tagged Remove the ring ports from the default VLAN delete vlan 1 port 1 2 Configure EPSR create epsr domainl mode transit controlvlan vlan1000 add epsr domain1 datavlan vlan2 enable epsr domainl Configure the STP VLAN create vlan vlan10 vid 10 add vlan 10 port 10 11 frame tagged Remove the STP VLAN s ports from the default VLAN delete vlan 1 port 10 11 Configure STP create stp example add stp example vlan vlan10 enable stp example set stp example mode rapid Page 19 AlliedWare OS How To Note EPSR
60. w of control frames when a link breaks Control VLAN is forwarding Control VLAN is forwarding Data VLANs move from blocking Data VLANs are forwarding to forwarding Transit Node Transit Node Transit Transit Node Node 3 Data ports move from fowarding to blocking Master Node Health Message Control VLAN a Transit Node Link Down Message 2 Ring Down Flush FDB Message G m epsr broken ring Fault in the master node If the master node goes down the transit nodes simply continue forwarding traffic around the ring their operation does not change The only observable effects on the transit nodes are that They stop receiving Health messages and other messages from the master node The transit nodes connected to the master node experience a broken link so they send Link Down messages If the master node is down these messages are simply dropped Neither of these symptoms affect how the transit nodes forward traffic Once the master node recovers it continues its function as the master node Page 6 Allied Ware OS How To Note EPSR How EPSR Works Restoring Normal Operation Master Node Once the fault has been fixed the master node s Health messages traverse the whole ring and arrive at the master node s secondary port The master node then restores normal conditions by declaring the ring to be in a state of Complete 2 blocking its secon
61. w that the ring is back up the master node blocks its secondary port for the data VLAN transmits a Ring Up Flush FDB message flushes its FDB sends a trap and changes the EPSR state to Complete Block EPSR test port 2 VLAN 2 EPSR Porti Tx 00602500 00040000 cd280619 8100e3e8 005caaaa 0300 020 00bb0100 00541fea 00000000 0000 28 0619990b 00400106 03e80000 00000000 cd280619 00000000 01000000 EPSR Portl Tx TYPE RING UP FLUSH FDB STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Flush FDB EPSR test vid 2 EPSR INFO Send trap EPSR test oldState FAILED newState COMPLETE nodeType MASTER EPSR test oldState FAILED newState COMPLETE 9 The master node receives the Ring Up Flush FDB message on port 2 The master node receives the Ring Up Flush FDB message back on its secondary port because the packet traversed the whole ring The master node ignores the message EPSR Port2 Rx 00e02500 00040000 cd280619 8100e3e8 005caaaa 0300e02b 00bb0100 00541fea 00000000 0000ca28 0619990b 00400106 03e80000 00000000 cd280619 00000000 01000000 EPSR Port2 Rx TYPE RING UP FLUSH FDB STATE COMPLETE CTRL VLAN 1000 SYSTEM 00 00 cd 28 06 19 HELLO TIME 0 FAIL TIME 0 HELLO SEQ 0 Page 51 AlliedWare OS How To Note EPSR Debugging 10 The master node trans
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