11-28-2019 01:52 PM
Hello all,
I am trying to set up a MPLS with BGP core, using confederations in order to have the iBGP full mesh. While configuring it, I faced this situation
R1 establishes an eBGP connection with R2
R2 establishes an iBGP connection with R3
R1 and R3 are PE routers, therefore they have the 'address-family ipv4 vrf VRF_NAME' and the respective VRF configured on it.
After activating the neighbors in the 'address-family vpnv4' I see that the neighbors are up but no prefixes are being exchanged between R1 <-> R2 and R2 <-> R3. As a result R1 does not get the vpnv4 prefixes learned by R3 and viceversa.
While debugging it I decided to create the VRF in R2 as well, and to create 'address-family ipv4 vrf VRF_NAME ' in the bgp configuration. This worked, but I have not found any explanation whether this is the right way to configure it or not.
Normally I configure the BGP core using Route Reflectors and with this approach the VRF(s) and the 'address family ipv4 vrf VRF_NAME' do not have to be configured on the RR Router.
Here the configuration of the BGP processes
!------------------------------------------!
!---R3
router bgp 65023
bgp log-neighbor-changes
bgp confederation identifier 65000
bgp confederation peers 65121
no bgp default ipv4-unicast
neighbor 192.168.0.1 remote-as 65121
neighbor 192.168.0.1 ebgp-multihop 255
neighbor 192.168.0.1 update-source Loopback0
neighbor 192.168.0.2 remote-as 65023
neighbor 192.168.0.2 update-source Loopback0
!
address-family ipv4
network 192.168.0.3 mask 255.255.255.255
neighbor 192.168.0.2 activate
neighbor 192.168.0.2 next-hop-self
exit-address-family
!
address-family vpnv4
neighbor 192.168.0.2 activate
neighbor 192.168.0.2 send-community extended
exit-address-family
!
address-family ipv4 vrf SiteA
network 192.168.100.3 mask 255.255.255.255
redistribute ospf 10
exit-address-family
!------------------------------------------!
!---R2
iosv-2#sh run | s bgp
router bgp 65023
bgp log-neighbor-changes
bgp confederation identifier 65000
bgp confederation peers 65108 65121
no bgp default ipv4-unicast
neighbor 192.168.0.1 remote-as 65121
neighbor 192.168.0.1 ebgp-multihop 3
neighbor 192.168.0.1 update-source Loopback0
neighbor 192.168.0.3 remote-as 65023
neighbor 192.168.0.3 update-source Loopback0
neighbor 192.168.0.8 remote-as 65108
neighbor 192.168.0.8 ebgp-multihop 3
neighbor 192.168.0.8 update-source Loopback0
!
address-family ipv4
network 192.168.0.2 mask 255.255.255.255
neighbor 192.168.0.1 activate
neighbor 192.168.0.1 send-community
neighbor 192.168.0.3 activate
neighbor 192.168.0.3 send-community
neighbor 192.168.0.8 activate
neighbor 192.168.0.8 send-community
exit-address-family
!
address-family vpnv4
neighbor 192.168.0.1 activate
neighbor 192.168.0.1 send-community extended
neighbor 192.168.0.3 activate
neighbor 192.168.0.3 send-community extended
exit-address-family
!
! I had to create this, in addition to the respective vrf
address-family ipv4 vrf SiteA
exit-address-family
!------------------------------------------!
!---R1
router bgp 65121
bgp log-neighbor-changes
bgp confederation identifier 65000
bgp confederation peers 65023 65108
no bgp default ipv4-unicast
neighbor 192.168.0.2 remote-as 65023
neighbor 192.168.0.2 ebgp-multihop 3
neighbor 192.168.0.2 update-source Loopback0
neighbor 192.168.0.3 remote-as 65023
neighbor 192.168.0.3 ebgp-multihop 255
neighbor 192.168.0.3 update-source Loopback0
neighbor 192.168.0.12 remote-as 65121
neighbor 192.168.0.12 update-source Loopback0
!
address-family ipv4
network 192.168.0.1 mask 255.255.255.255
neighbor 192.168.0.2 activate
neighbor 192.168.0.2 next-hop-self
neighbor 192.168.0.12 activate
neighbor 192.168.0.12 next-hop-self
exit-address-family
!
address-family vpnv4
neighbor 192.168.0.2 activate
neighbor 192.168.0.2 send-community extended
neighbor 192.168.0.2 next-hop-self
exit-address-family
!
address-family ipv4 vrf SiteA
network 192.168.100.1 mask 255.255.255.255
redistribute ospf 10
exit-address-family
!---------------------------------
I will appreciate any help
Regards
Solved! Go to Solution.
11-28-2019 03:01 PM - edited 11-28-2019 03:02 PM
By default, IOS filters out routes for which we do not have a matching VRF defined locally. To disable this default behavior, you need to use the following command: "no bgp default route-target filter". You would need to use this command on R2.
Regards,
11-28-2019 03:01 PM - edited 11-28-2019 03:02 PM
By default, IOS filters out routes for which we do not have a matching VRF defined locally. To disable this default behavior, you need to use the following command: "no bgp default route-target filter". You would need to use this command on R2.
Regards,
11-28-2019 03:35 PM
11-28-2019 09:59 PM
Did you clear the BGP sessions on R2?
Regards,
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