OSPF in LAN, BGP in WAN resilient design issue queries

Unanswered Question


I am trying to decide best way to implement reliable and predictable resilience in a multisite OSPF/BGP network.

2 main sites A and B(linked by a 100Mbps LES) each with a separate BGP AS and individual link to BGP WAN (the B site is about to be connected)

many other sites around globe linked over a BGP network (each with own AS)

sites A&B run 10.A.x.x/16 and 10.B.x.x/16

Within site A OSPF is run

within Site B OSPF is run (currently same OSPF as A)

other sites may also use OSPF in LAN (but not running OSPF directly over WAN

All sites need resilience

A is to get resilience via B (over LES) and vice versa if the local wan fails

I dont know if I should continue to run OSPF between sites A and B via LES or run BGP across this link and keep OSPF separate between A and B

Also should i use dynamic OSPF <> BGP redistributions or use hardcoded network statement in the BGP?

can anyone offer any ideas or advice please?

potential issues are complexity, possibility of routing loops / asymettric routing, predictability/stability.

each site should use local WAN link preferentially, and fall back to other site wan link in event of a failure.

any pointers to relevant design doc might be useful too.


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
smitty6504 Thu, 01/03/2008 - 12:05
User Badges:

We are doing something like what you are talking about.... We are running 2 3845 with eBGP to ISP then iBGP between the two 3845 routers. Then OSPF between the 3845's and our ASA's.


This Discussion