admin distances

Unanswered Question
Jul 18th, 2008

I'm preparing a environment where my firewall will create a tunnel to a remote site that I normall access via our WAN, but want to access via a tunnel when that wan connection is down. When my firewall redistributed its static route to 10.10.1.0/24 (the network reachable via the WAN under normal circumstances) via the tunnel(Internet) into eigrp, and then eigrp communicated that to the my wan router, it should have come over with an admin distance of 170 on the wan router. Meanwhile, the hbg wan router should have had a route to 10.10.1.0/24 via eBGP with an admin distance of 20. What happened is my wan router started routing traffic for 10.10.1.0/24 via the firewall instead of the WAN. Why did it choose the eigrp learned route? Is an IGP route preferred over an eBGP route despite the difference in admin distance?

thank you,

Bill

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
Jerry Ye Fri, 07/18/2008 - 12:00

You are obsolute right on how the router is choosing the route with the following logic

1) more specific route win

2) lowest admin distance win

3) lowest metric win

Can you post couple show command outputs?

show ip route 10.10.1.0

show ip bgp 10.10.1.0

show ip eigrp top 10.10.1.0 255.255.255.0

Regards,

jerry

WILLIAM STEGMAN Fri, 07/18/2008 - 12:30

thanks, I actually took the route out, because it affected my production network. Having you confirm my understanding helps. I'll try recreating in a a lab or trying again outside business hours.

thanks again

WILLIAM STEGMAN Fri, 07/18/2008 - 14:04

it was a longer mask that caused the route path to change. I was learning about a /16 via BGP, and a /24 via EIGRP.

Actions

This Discussion