cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
529
Views
0
Helpful
2
Replies

Filter one IP from redistributing into BGP

thrtnastrx2
Level 1
Level 1

We have a datacenter and several branch offices that connect to the datacenter via MPLS and backup Internet VPN. Our primary routing protocol is EIGRP (LAN and VPN), which is redistributed into our MPLS via BGP. Our primary connection for all IP traffic is MPLS and backup is VPN, however for a couple IP's in our datacenter I need the reverse (primary VPN and backup MPLS). I did this using PBR at the datacenter and a static route at the branch office as a POC, now I would like to do this using dynamic routing but I am trying to avoid touching 200+ branch office routers. Is is possible to redistribute the datacenter subnet into BGP minus the single IP which would remain only in EIGRP?

Datacenter subnet 172.31.10.0/24
Server IP - 172.31.10.100/32

2 Replies 2

Hello


@thrtnastrx2 wrote:

 I would like to do this using dynamic routing but I am trying to avoid touching 200+ branch office routers. Is is possible to redistribute the datacenter subnet into BGP minus the single IP which would remain only in EIGRP?


You could look into a couple of conditional route advertisements features for bgp.


First the bgp backdoor feature, Which basically would increase the admin distance of these specific received routes which would then allow the router to prefer the same prefixes via eigrp and if the eigrp link was to fail then the mpls path for these routes would be viable.

example1:

router bgp 11
network 22.22.2.0 mask 255.255.255.0 backdoor  <---route received for bgp peer

router bgp 22
network 11.11.11.0 mask 255.255.255.0 backdoor <---route received for bgp peer

Another option would to only advertise routes over the mpls if the routes via eigrp failed.

 

Example2
Access-list 11 permit 11.11.11.0 0.0.0.255  <- mpls and eigrp route
Access-list 22 permit 2.2.2.0 0.0.0.255 <- eigrp route

route-map MPLS_route
match ip address 11

route-map Eigrp_route
match ip address 22

router bgp x
neigbour x.x.x.x advertise-map MPLS_route non-exist-map Eigrp route


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

I will try this and report back.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: