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Seeking help to build a shared infrastructure

Badshah
Level 1
Level 1

Hi all,

I'm trying to configure a shared infrastructure with VRF light for two imaginary customers.

VRF Light.png* R2 & CRB2 have identical BGP configuration such as same ASN, WAN IP, BGP router id and network advertisement.
* I have created two separate VRFs at R5 and established eBGP neighborship among them (R2 & CRB2 ).
* I have set two separate community values for two customers towards global RT.

Now, R5 (Global RT) is choosing only routes from VRF "B". What should I do if I want to keep both routes from VRF "A" and VRF "B" and separate in global RT?

R5#sh ip bg
BGP table version is 33, local router ID is 198.51.100.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
t secondary path,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

Network Next Hop Metric LocPrf Weight Path

* 172.16.1.0/24 192.168.1.6 0 0 65200 i
*> 192.168.1.6 0 0 65200 i


R5#sh ip bg 172.16.1.0/24
BGP routing table entry for 172.16.1.0/24, version 32
Paths: (2 available, best #2, table default)
Advertised to update-groups:
3
Refresh Epoch 1
65200, imported path from 474:100:172.16.1.0/24 (A)
192.168.1.6 from 192.168.1.6 (192.168.1.6)
Origin IGP, metric 0, localpref 100, valid, external
Community: 31064164
Extended Community: RT:474:100
rx pathid: 0, tx pathid: 0
Refresh Epoch 1
65200, imported path from 474:200:172.16.1.0/24 (B)
192.168.1.6 from 192.168.1.6 (192.168.1.6)
Origin IGP, metric 0, localpref 100, valid, external, best
Community: 31064264
Extended Community: RT:474:200
rx pathid: 0, tx pathid: 0x0
R5#

*********************************************************

R5 running configuration

ip vrf A
rd 474:100
import ipv4 unicast map GLOBAL-VRFA
export ipv4 unicast map VRFA-GLOBAL
route-target export 474:100
route-target import 474:100
!
ip vrf B
rd 474:200
import ipv4 unicast map GLOBAL-VRFB
export ipv4 unicast map VRFB-GLOBAL
route-target export 474:200
route-target import 474:200

interface GigabitEthernet0/1
ip vrf forwarding A
ip address 192.168.1.5 255.255.255.252
duplex auto
speed auto
media-type rj45
!
interface GigabitEthernet0/2
ip vrf forwarding B
ip address 192.168.1.5 255.255.255.252
duplex auto
speed auto
media-type rj45
!

router bgp 474
bgp router-id 198.51.100.5
bgp log-neighbor-changes
neighbor 198.51.100.6 remote-as 474
!
address-family ipv4
neighbor 198.51.100.6 activate
neighbor 198.51.100.6 send-community both
neighbor 198.51.100.6 next-hop-self
exit-address-family
!
address-family ipv4 vrf A
neighbor 192.168.1.6 remote-as 65200
neighbor 192.168.1.6 activate
exit-address-family
!
address-family ipv4 vrf B
neighbor 192.168.1.6 remote-as 65200
neighbor 192.168.1.6 activate
exit-address-family
!
ip forward-protocol nd
!
ip community-list 1 permit 31064164
ip community-list 2 permit 31064264
!
route-map GLOBAL-VRFA permit 10
match community 1
!
route-map VRFA-GLOBAL permit 10
set community 31064164
!
route-map GLOBAL-VRFB permit 10
match community 2
!
route-map VRFB-GLOBAL permit 10
set community 31064264
!

4 Replies 4

I think you need under the address-family IPv4 
multi path ibgp or multi path ebgp 

MHM 

Hi MHM,

Thank you so much for your suggestion. So far my understanding, ibgp or eibgp multipath is for load sharing over multiple paths towards outbound traffic. My intention is opposite. I want to receive same prefix from two different ebgp neighbors.    

Regards,

Badshah Sekendar

both branches have same 172.16.1.0/24 and if it use same RD then both see as same prefix 
so if you want to see both prefix in BGP use different RD and if you want to use both prefix (i.e. in RIB) use multi path

MHM

Hi MHM,

The prefixes are already in different RDs. I have added the multipath as well, nothing got changed unfortunately. 

Current BGP config

address-family ipv4
neighbor 198.51.100.6 activate
neighbor 198.51.100.6 send-community both
neighbor 198.51.100.6 next-hop-self
maximum-paths eibgp 2
exit-address-family

BGP table

R5(config-router-af)#do sh ip bg 172.16.1.0/24
BGP routing table entry for 172.16.1.0/24, version 6
Paths: (2 available, best #2, table default)
Advertised to update-groups:
2
Refresh Epoch 1
65200, imported path from 474:100:172.16.1.0/24 (A)
192.168.1.6 from 192.168.1.6 (192.168.1.6)
Origin IGP, metric 0, localpref 100, valid, external
Community: 31064164
Extended Community: RT:474:100
rx pathid: 0, tx pathid: 0
Refresh Epoch 1
65200, imported path from 474:200:172.16.1.0/24 (B)
192.168.1.6 from 192.168.1.6 (192.168.1.6)
Origin IGP, metric 0, localpref 100, valid, external, best
Community: 31064264
Extended Community: RT:474:200
rx pathid: 0, tx pathid: 0x0

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