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Professional Discussions => Routing and Switching => Topic started by: Ironman on August 07, 2015, 02:30:32 PM

Title: BGP Received Routes Command
Post by: Ironman on August 07, 2015, 02:30:32 PM
Hey everyone, so I been doing some reading and I am trying to find out the difference between the following 2 BGP (Cisco) Commands:

show ip bgp neighbor x.x.x.x received-routes

show ip bgp neighbor x.x.x.x routes

I come across a lot of production routers not having the soft-reconfiguration inbound command so the received-routes command does not work. I have always just used the routes command. Am I overlooking something? Are these not the same commands in essence?

TEST_R2#sho ip bgp nei 1.1.1.1 received-routes
BGP table version is 8, local router ID is 172.19.1.1
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,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
r>  1.1.1.1/32       1.1.1.1                  0             0 65001 ?
*>  172.16.1.0/24    1.1.1.1                  0             0 65001 i
*>  172.17.1.0/24    1.1.1.1                  0             0 65001 i
*   192.168.0.0/30   1.1.1.1                  0             0 65001 ?

Total number of prefixes 4

TEST_R2#sho ip bgp nei 1.1.1.1 routes
BGP table version is 8, local router ID is 172.19.1.1
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,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
r>  1.1.1.1/32       1.1.1.1                  0             0 65001 ?
*>  172.16.1.0/24    1.1.1.1                  0             0 65001 i
*>  172.17.1.0/24    1.1.1.1                  0             0 65001 i
*   192.168.0.0/30   1.1.1.1                  0             0 65001 ?

Total number of prefixes 4

Title: Re: BGP Received Routes Command
Post by: packetherder on August 07, 2015, 02:51:42 PM
First one is pre-filtering and the other post, iirc.
Title: Re: BGP Received Routes Command
Post by: Ironman on August 07, 2015, 03:31:34 PM
So Routes-Received shows routes placed in the routing table and just routes shows all routes learned?
Title: Re: BGP Received Routes Command
Post by: wintermute000 on August 07, 2015, 05:48:17 PM
No.... not what he said

To recap:
http://ccie-in-3-months.blogspot.com/2008/04/bgp-how-to-display-incomingoutgoing.html (http://ccie-in-3-months.blogspot.com/2008/04/bgp-how-to-display-incomingoutgoing.html)


IMO this is pretty much the only advantage to soft-reconfiguration inbound vs route-refresh
Title: Re: BGP Received Routes Command
Post by: Ironman on August 07, 2015, 08:00:58 PM
Quote from: wintermute000 on August 07, 2015, 05:48:17 PM
No.... not what he said

To recap:
http://ccie-in-3-months.blogspot.com/2008/04/bgp-how-to-display-incomingoutgoing.html (http://ccie-in-3-months.blogspot.com/2008/04/bgp-how-to-display-incomingoutgoing.html)


IMO this is pretty much the only advantage to soft-reconfiguration inbound vs route-refresh

Ahhhh, thanks for the link! So the show routes command shows just what was placed into the routing table vs the received-routes which shows all routes received and has indicators showing how BGP treats that prefix. Thanks for the clarification!
Title: Re: BGP Received Routes Command
Post by: srg on August 08, 2015, 03:04:44 AM
Quote from: Ironman on August 07, 2015, 08:00:58 PM
Quote from: wintermute000 on August 07, 2015, 05:48:17 PM
No.... not what he said

To recap:
http://ccie-in-3-months.blogspot.com/2008/04/bgp-how-to-display-incomingoutgoing.html (http://ccie-in-3-months.blogspot.com/2008/04/bgp-how-to-display-incomingoutgoing.html)


IMO this is pretty much the only advantage to soft-reconfiguration inbound vs route-refresh

Ahhhh, thanks for the link! So the show routes command shows just what was placed into the routing table vs the received-routes which shows all routes received and has indicators showing how BGP treats that prefix. Thanks for the clarification!
No they basically show the same things with the difference that 'received-routes' are pre local filtering in adj-RIB-in and 'routes' are post local filtering from loc-RIB. Neither are not necessarily placed in the actual routing table.
Title: Re: BGP Received Routes Command
Post by: wintermute000 on August 08, 2015, 05:11:54 AM
yeah, drill it into your head: BGP table is NOT the routing table. BGP routes will fight it out in the BGP table before entering the RiB.
You'll come to love it and wonder why the heck other protocols don't give you this wonderful resource :) (well they sort of do, but the OSPF database is really cryptic by comparison!)
Title: Re: BGP Received Routes Command
Post by: Ironman on August 08, 2015, 10:16:29 AM
I agree with the OSPF database being cryptic. I do like the EIGRP topology table.

Anyways, thanks the hints fellas!
Title: Re: BGP Received Routes Command
Post by: burnyd on August 08, 2015, 10:31:24 AM
This was very confusing to me as well when I used XR for the first time.
Title: Re: BGP Received Routes Command
Post by: srg on August 08, 2015, 11:56:10 AM
Quote from: burnyd on August 08, 2015, 10:31:24 AM
This was very confusing to me as well when I used XR for the first time.
How is this different in XR?