Import vrf and route-map issue

[josh-yangcching]

• Problem Statement
  I am using frr 10.4.1 to config as the following topology. The question is that why there is only one path instead of two path in output of "show ipv6 route vrf vrf-blue" in node "frr-10.4.1-3". But there are two paths from the output of "show bgp vrf vrf-blue 2a02:6bf:8009:ff06::/64". It looks like that it used path from vrf-red instead of route-map results.

frr-10.4.1-3# show ipv6 route vrf vrf-blue
Codes: K - kernel route, C - connected, L - local, S - static,
       R - RIPng, O - OSPFv3, I - IS-IS, B - BGP, N - NHRP,
       T - Table, v - VNC, V - VNC-Direct, A - Babel, F - PBR,
       f - OpenFabric, t - Table-Direct,
       > - selected route, * - FIB route, q - queued, r - rejected, b - backup
       t - trapped, o - offload failure

IPv6 unicast VRF vrf-blue:
B>* 2a02:6bf:8009:ff06::/64 [20/0] via fe80::42:28ff:fec4:c803, eth1 (vrf vrf-red), weight 1, 00:21:27

frr-10.4.1-3# show bgp vrf vrf-blue 2a02:6bf:8009:ff06::/64
BGP routing table entry for 2a02:6bf:8009:ff06::/64, version 2
Paths: (2 available, best #1, vrf vrf-blue)
  Not advertised to any peer
  Imported from 10.10.10.10:2:2a02:6bf:8009:ff06::/64
  1 2 11
    fe80::42:28ff:fec4:c803 from :: (0.0.0.0) vrf vrf-red(2) announce-nh-self
    (fe80::42:28ff:fec4:c803) (used)
      Origin IGP, valid, sourced, local, best (AS Path)
      Originator: 0.0.0.0
      Last update: Fri Aug 29 09:10:25 2025
  Imported from 10.10.10.10:2:2a02:6bf:8009:ff06::/64
  1 2 11
    fe80::42:4dff:fe47:8202 from :: (0.0.0.0) vrf vrf-red(2) announce-nh-self
    (fe80::42:4dff:fe47:8202) (used)
      Origin IGP, valid, sourced, local
      Community: 6500:6400
      Originator: 0.0.0.0
      Last update: Fri Aug 29 09:10:25 2025

• expected result:
  there are two paths in output of "show ipv6 route vrf vrf-blue" which is the same as output of "show bgp vrf vrf-blue 2a02:6bf:8009:ff06::/64"

• the topology:

• the config

  • frr-10.4.1-1
    ip conifg:

  eth1: 192.0.1.2/30
  eth2: 192.0.4.1/30
  

  frr config

    Building configuration...
    Current configuration:
    !
    frr version 10.4.1_git
    frr defaults traditional
    hostname frr-10.4.1-1
    !
    route-map test permit 10
     set community 6500:6400
    exit
    !
    router bgp 1
     bgp router-id 1.1.1.1
     no bgp ebgp-requires-policy
     neighbor 192.0.1.1 remote-as 2
     neighbor 192.0.4.2 remote-as 10
     !
     address-family ipv6 unicast
      neighbor 192.0.1.1 activate
      neighbor 192.0.4.2 activate
      neighbor 192.0.4.2 route-map test out
     exit-address-family
    exit
    !
    end
  

  • frr-10.4.1-2
    ip conifg:

  eth1: 192.0.1.1/30
  eth2: 192.0.2.1/30
  eth3: 192.0.3.1/30
  

  frr config

    Building configuration...
    Current configuration:
    !
    frr version 10.4.1_git
    frr defaults traditional
    hostname frr-10.4.1-2
    !
    route-map test permit 10
     set community 6500:6400
    exit
    !
    router bgp 2
     bgp router-id 2.2.2.2
     no bgp ebgp-requires-policy
     neighbor 192.0.1.2 remote-as 1
     neighbor 192.0.2.2 remote-as 11
     neighbor 192.0.3.2 remote-as 10
     !
     address-family ipv6 unicast
      neighbor 192.0.1.2 activate
      neighbor 192.0.2.2 activate
      neighbor 192.0.3.2 activate
     exit-address-family
    exit
    !
    end
  

  • frr-10.4.1-3
    ip conifg:

  eth1: 192.0.3.2/30
  eth2: 192.0.4.2/30
  

  frr config

    Building configuration...
    Current configuration:
    !
    frr version 10.4.1_git
    frr defaults traditional
    hostname frr-10.4.1-3
    !
    route-map VRF_ToR_IMPORT permit 10
     match community DF_REANONCE
    exit
    !
    route-map VRF_ToR_IMPORT permit 100
     set as-path prepend 1
    exit
    !
    vrf vrf-blue
    exit-vrf
    !
    vrf vrf-red
    exit-vrf
    !
    router bgp 10
    exit
    !
    router bgp 10 vrf vrf-red
     bgp router-id 10.10.10.10
     no bgp ebgp-requires-policy
     bgp bestpath as-path multipath-relax
     neighbor 192.0.3.1 remote-as 2
     neighbor 192.0.4.1 remote-as 1
     !
     address-family ipv6 unicast
      neighbor 192.0.3.1 activate
      neighbor 192.0.4.1 activate
     exit-address-family
    exit
    !
    router bgp 10 vrf vrf-blue
     bgp bestpath as-path multipath-relax
     !
     address-family ipv6 unicast
      import vrf route-map VRF_ToR_IMPORT
      import vrf vrf-red
     exit-address-family
    exit
    !
    bgp community-list standard DF_REANONCE seq 5 permit 6500:6400
    !
    end
  

  • frr-10.4.1-4
    ip conifg:

  eth1: 192.0.2.2/30
  

  frr config

  Building configuration...
  Current configuration:
  !
  frr version 10.4.1_git
  frr defaults traditional
  hostname frr-10.4.1-4
  !
  router bgp 11
   no bgp ebgp-requires-policy
   neighbor 192.0.2.1 remote-as 2
   !
   address-family ipv6 unicast
    network 2a02:6bf:8009:ff06::/64
    neighbor 192.0.2.1 activate
   exit-address-family
  exit
  !
  end
  

[josh-yangcching]

I also tried the version: 8.1 with the same config. Here is the output which have two path for the same route. The result is different from testing with version: 10.4.1. I found that there is a PR: #9610, which may let route check from vrf parent. The question is that if there is also config "import vf route-map", which behavior is correct?

frr-v8.1.0-3# show ipv6 route vrf vrf-blue
Codes: K - kernel route, C - connected, S - static, R - RIPng,
       O - OSPFv3, I - IS-IS, B - BGP, N - NHRP, T - Table,
       v - VNC, V - VNC-Direct, A - Babel, F - PBR,
       f - OpenFabric,
       > - selected route, * - FIB route, q - queued, r - rejected, b - backup
       t - trapped, o - offload failure

VRF vrf-blue:
B>* 2a02:6bf:8009:ff06::/64 [20/0] via fe80::42:1ff:fe67:203, eth1 (vrf vrf-red), weight 1, 00:00:09
  *                                via fe80::42:f2ff:fed2:4102, eth2 (vrf vrf-red), weight 1, 00:00:09```
 

frr-v8.1.0-3# show bgp vrf vrf-blue 2a02:6bf:8009:ff06::/64
BGP routing table entry for 2a02:6bf:8009:ff06::/64, version 2
Paths: (2 available, best #1, vrf vrf-blue)
  Not advertised to any peer
  Imported from 10.10.10.10:2:2a02:6bf:8009:ff06::/64
  1 2 11
    fe80::42:1ff:fe67:203 from :: (0.0.0.0) vrf vrf-red(2)
    (fe80::42:1ff:fe67:203) (used)
      Origin IGP, valid, sourced, local, multipath, best (Locally configured route)
      Originator: 0.0.0.0
      Last update: Mon Sep  1 03:04:49 2025
  Imported from 10.10.10.10:2:2a02:6bf:8009:ff06::/64
  1 2 11
    fe80::42:f2ff:fed2:4102 from :: (0.0.0.0) vrf vrf-red(2)
    (fe80::42:f2ff:fed2:4102) (used)
      Origin IGP, valid, sourced, local, multipath
      Community: 6500:6400
      Originator: 0.0.0.0
      Last update: Mon Sep  1 03:04:49 2025