Thank you.  These slides are a little bit more informative. I tried to enter "rep stcn stp"  command but it says : Command Rejected: For Edge no-neighbor ports, stcn stp is allowed only if spanning-tree mode is mst So it doesn't work. What if I enter command "rep stcn segment " command instead ? Will ASR recognize those TCN's or are they incompatibile with the code ? I ask because I tried it and when there is some REP ring change (link goes down) for example I don't see any TCN flushes counters increasing :-( ? "show spanning-tree repag RING_TEST topology-change flushes " I guess that no TCN's are sent. Also, if admin VLAN is not default (1) but 96 - does it mean that TCN mesaages are sent via VLAN 96 ?  ... View more

Thank you. I have found on ciscolive BRKSPG-2202, page 89 on pdf document that switch end ports should be configured as "rep edge no-neighbor". This is why I have some doubts. There is no straightforward config documentation for using REP-AG, or at least I couldn't find it. It really behaves different if you put the port on switch as "edge no neighbor" or not. Also, could you comment my config related to ".1" subinterface please ? I have configured subif 0/0/0/2.1 toward REP access ring switches, and it is attached to spanning-tree repag configuration (you can see my config in previous mail). On the other hand I have configured interface 0/0/0/1.1 between two ASR routers for propagating TCN's between ASR's. And my question was - this TCN exchange VLAN must be ".1" , right ? Allthough we use REP admin VLAN 96 in REP access ring ? thank you again, Tom ... View more

Hello Xander,  could you explain a little bit what would be correct configuration for REP-AG in a ring described in lower topology? We have 2 ASR9K on each REP segment end. REP admin VLAN is 96. REP segment is 201 carrying all vlans.  On switch ports connecting to ASR 9k on both ends (0/13 on sw1 and 0/15 on sw3) do we have to configure rep segment 201 command ? Or is it just plain switchport mode trunk ? Do we have to configure REP edge command on ASR9k ? It is allways mentioned in config guides that we have to enable  x/x/x/x.1 encapsulation untagged subinterface. What if admin VLAN is 96 like in our case ? I guess we have to use ".1" anyway. Does rep instance in spanning-tree repag configuration have to match REP segment 201 ? And  Here is config of one ASR9K: spanning-tree repag RING_TEST preempt delay for 2 seconds interface GigabitEthernet0/0/0/2.1 instance 201 vlan-ids 1-4094 priority 4096 edge-mode root-priority 4096 RP/0/RSP0/CPU0:SW-ASR9k-LAB-5# sh run int gigabitEthernet 0/0/0/2.1 Wed Jun 7 14:02:36.160 CET interface GigabitEthernet0/0/0/2.1 l2transport encapsulation untagged ! RP/0/RSP0/CPU0:SW-ASR9k-LAB-5# sh run int gigabitEthernet 0/0/0/1.1 Wed Jun 7 14:02:39.571 CET interface GigabitEthernet0/0/0/1.1 l2transport encapsulation untagged l2vpn tcn-propagation bridge group REP_test bridge-domain RING_TCN interface GigabitEthernet0/0/0/2.1 interface GigabitEthernet0/0/0/1.1 Thank you ... View more

Hy,  it seems there is no such elegant solution, at least I cannot find it and I'm looking for quite some time. I don't understand why they didn't implement it in IOS XR. All sugestions I have seen are going in direction to implement some kind of route-policies which complicates things. Solution is simple by itself, but when you have many TE-tunnels you end up with messy configuration in VPNV4 part. regards ... View more

Hy,  just to see another issue with this topic. Let's say that we have Lo0 as global routing loopback and BGP router-id. And, we have Loop 100 for this TE purpose.  How to export from ASR and set next-hop ? I guess I can not do it inside global VRF config with export-policy right, because next-hop will be anyway  set to Loopback0 toward VPNV4 route-reflector, and not Loopback 100 right ? ... View more

Hello,  I have attached a little drawing also if that can help. It is rather simple LAB topology.  Also outputs of show commands. Please, help on this if you can, or if you would rather suggest that I open TAC case for this . regards ... View more

Hello,  OK. But let's see following situation. I have ASR9k connected to switch via trunk interface. From that switch broadcast storm happens and it is propagated toward ASR9k interfaces. Interface config on ASR is: interface GigabitEthernet0/0/0/2 description sw-lab-1##Gi0/15#(3400-12) cdp service-policy output QOS_METRO_OUT negotiation auto load-interval 30 transceiver permit pid all ! interface GigabitEthernet0/0/0/2.5 description IPTV ipv4 address 172.26.38.36 255.255.255.224 shutdown load-interval 30 encapsulation dot1q 5 ! interface GigabitEthernet0/0/0/2.1905 l2transport description L2VPN-P2P encapsulation dot1q 1905 rewrite ingress tag pop 1 symmetric ! interface GigabitEthernet0/0/0/2.1908 l2transport description VPLS encapsulation dot1q 1908 rewrite ingress tag pop 1 symmetric service-policy input BS_VPN_2M ! interface GigabitEthernet0/0/0/2.2019 description L3VPN vrf ACS ipv4 address 10.128.127.2 255.255.255.240 encapsulation dot1q 2019 When we experience broadcast we see global routing flaps, we see NSR log messages and it definitely influences overall performance. Since we can not implement storm-control on physical interface how can we protect against such behaviour. Here are some log messages from affected ASR: RP/0/RSP0/CPU0:ASR-9K-LAB#RP/0/RSP0/CPU0:May 18 12:33:32.948 : tcp[445]: %IP-TCP_NSR-5-DISABLED : 85.94.144.18:27998 <-> 85.94.144.13:646:: NSR disabled for TCP connection because Retransmission threshold exceeded RP/0/RSP0/CPU0:May 18 12:33:35.051 : mpls_ldp[1192]: %ROUTING-LDP-5-NSR_SYNC_START : Initial synchronization started for 1 peers RP/0/RSP0/CPU0:May 18 12:33:56.600 : tcp[445]: %IP-TCP_NSR-5-DISABLED : 85.94.144.18:27998 <-> 85.94.144.13:646:: NSR disabled for TCP connection because Retransmission threshold exceeded RP/0/RSP0/CPU0:May 18 12:33:58.704 : mpls_ldp[1192]: %ROUTING-LDP-5-NSR_SYNC_START : Initial synchronization started for 1 peers RP/0/RSP0/CPU0:May 18 12:34:00.085 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from FULL to DOWN, Neighbor Down: dead timer expired, vrf default vrfid 0x60000000 LC/0/0/CPU0:May 18 12:34:00.089 : bfd_agent[125]: %L2-BFD-6-SESSION_REMOVED : BFD session to neighbor 85.94.144.237 on interface GigabitEthernet0/0/0/0 has been removed RP/0/RSP0/CPU0:May 18 12:34:01.139 : ipv4_rib[1160]: %ROUTING-RIB-7-SERVER_ROUTING_DEPTH : Recursion loop looking up prefix 195.29.110.201 in Vrf: "default" Tbl: "default" Safi: "Unicast" added by bgp RP/0/RSP1/CPU0:May 18 12:34:01.152 : ipv4_rib[1160]: %ROUTING-RIB-7-SERVER_ROUTING_DEPTH : Recursion loop looking up prefix 195.29.110.201 in Vrf: "default" Tbl: "default" Safi: "Unicast" added by bgp RP/0/RSP0/CPU0:May 18 12:34:01.354 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from DOWN to INIT, Received Hello, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:01.354 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from INIT to 2WAY, 2-Way Received, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:01.354 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from 2WAY to EXSTART, AdjOK?, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:01.358 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from EXSTART to EXCHANGE, Negotiation Done, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:01.381 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from EXCHANGE to LOADING, Exchange Done, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:01.384 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from LOADING to FULL, Loading Done, vrf default vrfid 0x60000000 LC/0/0/CPU0:May 18 12:34:01.390 : bfd_agent[125]: %L2-BFD-6-SESSION_DAMPENING_ON : Session to neighbor 85.94.144.237 on interface GigabitEthernet0/0/0/0 entered Dampened state (initial: 2000 ms,secondary: 5000 ms,maximum: 120000 ms). RP/0/RSP0/CPU0:May 18 12:34:05.384 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from FULL to DOWN, Neighbor Down: dead timer expired, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:06.113 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from DOWN to INIT, Received Hello, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:06.113 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from INIT to 2WAY, 2-Way Received, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:06.113 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from 2WAY to EXSTART, AdjOK?, vrf default vrfid 0x60000000 RP/0/RSP0/CPU0:May 18 12:34:06.115 : ospf[1018]: %ROUTING-OSPF-5-ADJCHG : Process 1, Nbr 85.94.144.2 on GigabitEthernet0/0/0/0 in area 0 from EXSTART to EXCHANGE, Negotiation Done, vrf default vrfid 0x60000000 ... View more

Hy Xander,  can you explain a little bit how is LPTS related to protecting from broadcast storms ? In IOS XR we can protect on bridge-domain by introducing storm-control, but we can not do it per physical interface basis. Meaning, what exactly happens when there is a L2 loop which generates broadcast storm on ASR physical interface and how does ASR resolve it ? For example, 7609 platform would regularly crash in similar situations without protection.  Thank you very much ... View more

Hy,  thank you very much for your effort. This is definitely way to go. regards ... View more

Thank you Xander. This was way to go since I couldn't find upper mentioned equivalent for IOS XR,  but I wanted to check first did I maybe miss something. regards ... View more

Hy, is there some IOS XR equivalent of following : vrf data rd 10000:100 route-target both 10000:100 bgp next-hop loopback100 where loopback 100 is used for MPLS TE traffic routing (per VRF MPLS TE).  In IOS XR there is no possibility to migrate configuration in similar way, so I would like to know is there some by-the-book proposed solution for that ? thank you ... View more

Hy,  do you know is there some guideline how to accomplish this MPLS TE  with per VRF/VPN feature in IOS XR. I cannot configure it under VRF, tried also to find it somehow under BGP VRF but without success. thank you very much ... View more

OK Xander, thank you very much for explanation. Last question :-) - do you have some numbers related to that or some testing experience - how much does that influence pps in real life ? For example, for same traffic with BVI's compared to traffic with subifs we have lets say 10% less pps or something like that ? ... View more

Thank you Xander. Can you explain a little bit this performance influence when using BVI - what is the difference when using BVI or subif related to pps ? Did you mean related to DHCP relay or are you talking in general ? regards ... View more