03-29-2010 11:14 AM - edited 03-04-2019 07:57 AM
Hi, can you confirm this:
Imagine that in production I have R1(internal network)----R2(ISP).
My task is to change config on R1 from static 'ip route 0.0.0.0 0.0.0.0 R2_IP' to BGP.
I already identified and tested in lab all BGP network statements and aggregate command I need to advertise - OK.
Question:
If I currently have a static route functional on R1 then I input my BGP statements, what would be the best way to minimize impact in production in case I missed a network statements or the provider misconfigured BGP from his side for whatever reason?
I mean, once I input the BGP statements, the static route has the lowest administrative distance and therefore routing should still occur via the default route, correct (unless there is a more specific match).
Please let me if you have ideas to minimize impact on this transition.
Solved! Go to Solution.
03-29-2010 11:40 AM
Dear Friend,
Pl change AD of Default route and also static like ,
ip route 0.0.0.0 0.0.0.0 xxx.xxx.xxx.xxx 250
ip route (ip address subnetmask nexthope ) 253
Then it should work on BGP route, cause BGP AD is 200
Hope to help.
Cheers!!!
Vaib...
03-29-2010 12:58 PM
Marlon
I mean, once I input the BGP statements, the static route has the lowest administrative distance and therefore routing should still occur via the default route, correct (unless there is a more specific match).
Correct. So you can configure your BGP and then check the BGP table and your routing table to make sure you have received all the necessary routes. Then as Vaib suggested you can simply modify the default-route to have an AD greater than your EBGP routes so that you still have a default-route but it is only used if BGP routes are not received.
Once you are happy you have all the routes then remove the static default-route.
Jon
03-29-2010 11:40 AM
Dear Friend,
Pl change AD of Default route and also static like ,
ip route 0.0.0.0 0.0.0.0 xxx.xxx.xxx.xxx 250
ip route (ip address subnetmask nexthope ) 253
Then it should work on BGP route, cause BGP AD is 200
Hope to help.
Cheers!!!
Vaib...
03-29-2010 12:58 PM
Marlon
I mean, once I input the BGP statements, the static route has the lowest administrative distance and therefore routing should still occur via the default route, correct (unless there is a more specific match).
Correct. So you can configure your BGP and then check the BGP table and your routing table to make sure you have received all the necessary routes. Then as Vaib suggested you can simply modify the default-route to have an AD greater than your EBGP routes so that you still have a default-route but it is only used if BGP routes are not received.
Once you are happy you have all the routes then remove the static default-route.
Jon
03-29-2010 01:09 PM
Thanks all!!!
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