BGP filter export L3VPN routes

[EasyNetDev]

Hi all,

I've success to export and import via MPLS + BGP different routes from different VRFs. But now I'm facing this situation: global routing table (GRT) in R01 has full table imported from the ISP. I want to export to R10, which is a smaller hardware devices with only 2GB of RAM, just a part of the GRT of R01.
I tried like this:

router bgp XXXXX
 neighbor 10.193.1.1 remote-as XXXXX
 neighbor 10.193.1.1 description R10-MPLS
 neighbor 10.193.1.1 update-source 10.190.0.1
 !
 address-family ipv4 unicast
  network 89.A.B.0/24 route-map BGP-own-prefixes
  no neighbor 10.193.1.1 activate
  label vpn export auto
  export vpn
  import vpn
 address-family ipv4 vpn
  neighbor 10.193.1.1 activate
  neighbor 10.193.1.1 soft-reconfiguration inbound
 exit-address-family
 vrf-policy DEFAULT-VRF-EXPORT
  rd 89.A.B.1:101
  export route-map BGP-own-prefixes
 exit-vrf-policy

Where BGP-own-prefixes is:

ip prefix-list pl-MYIPS seq 5 permit 89.A.B.0/24

route-map BGP-own-prefixes permit 100
 description Set communities for IPv4 prefixes
 match as-path AS-MYAS
 match ip address prefix-list pl-MYIPS
 set community XXXXX:2000 XXXXX:3000 XXXXX:3502 XXXXX:4000 XXXXX:4002 XXXXX:8000
 set extcommunity rt XXXXX:101
exit

For the now I'm trying to export just a prefix from the GRT, trying to apply XXXXX:101 extcommunity and then import it on R10.
I can't find in the documentation something about how to preselect some routes and apply extcommunity to them and only these routes to be exported via L3VPN.

Some outputs:

# do sh bgp ipv4 89.A.B.0/24
BGP routing table entry for 89.A.B.0/24, version 36774378
Paths: (3 available, best #3, table default)
  Advertised to non peer-group peers:
  10.190.0.2 89.C.D.E 92.C.D.E 178.C.D.E 193.C.D.E
  Local
    10.190.0.2 (metric 43) from 10.190.0.2 (89.A.B.4)
      Origin IGP, metric 0, localpref 1000, valid, internal
      Community: XXXXX:2000 XXXXX:3000 XXXXX:3502 XXXXX:4000 XXXXX:4002 XXXXX:8000
      Last update: Mon Jan 10 12:56:00 2022
  Local
    0.0.0.0 from 0.0.0.0 (89.A.B.1)
      Origin incomplete, metric 0, weight 32768, valid, sourced
      Community: XXXXX:4002
      Last update: Wed Jan 12 14:31:35 2022
  Local
    0.0.0.0 from 0.0.0.0 (89.A.B.1)
      Origin IGP, metric 0, weight 32768, valid, sourced, local, best (Weight)
      Community: XXXXX:2000 XXXXX:3000 XXXXX:3502 XXXXX:4000 XXXXX:4002 XXXXX:8000
      Extended Community: RT:XXXXX:101
      Last update: Thu Feb 17 13:20:05 2022

The other router has this config:

router bgp XXXXX
 bgp router-id 10.193.1.1
 no bgp suppress-duplicates
 bgp graceful-shutdown
 bgp graceful-restart
 neighbor 10.190.0.1 remote-as XXXXX
 neighbor 10.190.0.1 description R01-MPLS
 neighbor 10.190.0.1 update-source 10.193.1.1
 neighbor 10.190.0.2 remote-as 65002
 neighbor 10.190.0.2 local-as 65010
 neighbor 10.190.0.2 description R02-IPv4
 neighbor 10.190.0.2 ebgp-multihop 2
 neighbor 10.190.0.2 update-source 10.193.1.1
 !
 address-family ipv4 unicast
  redistribute connected route-map rm-R10-BGP-redistribute
  redistribute static route-map rm-R10-BGP-redistribute
  no neighbor 10.190.0.1 activate
  neighbor 10.190.0.2 soft-reconfiguration inbound
  neighbor 10.190.0.2 route-map rm-R10-received-02 in
  neighbor 10.190.0.2 route-map rm-R10-advertised-01 out
  label vpn export auto
  rt vpn import XXXXX:102 XXXXX:101
  export vpn
  import vpn
 exit-address-family
 !
 address-family ipv4 vpn
  neighbor 10.190.0.1 activate
  neighbor 10.190.0.1 soft-reconfiguration inbound
 exit-address-family
exit

[EasyNetDev]

Hi,

I found the solution. You need to set rt vpn export XXXXX:1000 and them use route-map under the ipv4 unicast:

router bgp XXXXX
 address-family ipv4 unicast
  label vpn export auto
  rd vpn export XXXXX:1000
  rt vpn export XXXXX:1000
  route-map vpn export VPN-MPLS-EXPORT
  export vpn
  import vpn

And the route-map it matches the prefixes you need to set specific extcommunity, like 65001:1000. On the other router you import only 65001:1000.