Re: BGP SoO

Hello experts,

Anyone who read this post able to answer my below query or perhaps Narbik
who wrote this lab :). Can we implement the solution without outgoing map
and only with incoming map or neighbors command.

After conducting more research , the below posts mention that outgoing map
is not required.

https://supportforums.cisco.com/message/963149

Thanks in advance-

Bilal Hansrod

On Thu, Jun 9, 2011 at 10:10 PM, Bilal Hansrod <bilal.hansrod_at_gmail.com>wrote:

> Hello Everyone,
>
> I am having difficulty understanding one of the Narbik's BGP SoO lab. Here
> is the lab setup removing unnecessary components :
>
> R4 acting as a PE is dual homed to R5 CE via FR p-2-p and serial link. R5
> (CE) is advertising it's loopback 5.5.5.5 to R4 via link and it learned same
> route back from R4. The BGP table on R5 looks like this:
>
> R5#show ip bgp
>
> BGP table version is 37, local router ID is 5.5.5.5
>
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal,
>
> r RIB-failure, S Stale
>
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
>
> * 1.0.0.0 10.1.100.4 0 65001 65015 i
>
> *> 10.1.45.4 0 65001 65001 i
>
> * 5.0.0.0 10.1.100.4 0 65001 65015 i
>
> *> 0.0.0.0 0 32768 i
>
> * 192.168.1.0 10.1.100.4 0 65001 65015 i
>
> *> 10.1.45.4 0 65001 65001 i
>
> * 192.168.5.0 10.1.100.4 0 65001 65015 i
>
> *> 0.0.0.0 0 32768 i
>
> Once I implement the BGP SoO via route-map or neighbour command, the BGP
> table on R5 stop learning it's loopback 5.5.5.5 from frame connection.
>
> R5#show ip bgp
>
> BGP table version is 43, local router ID is 5.5.5.5
>
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal,
>
> r RIB-failure, S Stale
>
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
>
> * 1.0.0.0 10.1.100.4 0 65001 65015 i
>
> *> 10.1.45.4 0 65001 65001 i
>
> *> 5.0.0.0 0.0.0.0 0 32768 i
>
> * 192.168.1.0 10.1.100.4 0 65001 65015 i
>
> *> 10.1.45.4 0 65001 65001 i
>
> *> 192.168.5.0 0.0.0.0 0 32768 i
>
> It's all as per plan:
>
> R4 Configuration before BGP SoO
>
> router bgp 65001
>
> no bgp default ipv4-unicast
>
> bgp log-neighbor-changes
>
> neighbor 3.3.3.3 remote-as 65001
>
> neighbor 3.3.3.3 update-source Loopback0
>
> !
>
> address-family vpnv4
>
> neighbor 3.3.3.3 activate
>
> neighbor 3.3.3.3 send-community extended
>
> exit-address-family
>
> !
>
> address-family ipv4 vrf CB
>
> neighbor 10.1.45.5 remote-as 65015
>
> neighbor 10.1.45.5 activate
>
> neighbor 10.1.45.5 as-override
>
> neighbor 10.1.100.5 remote-as 65015
>
> neighbor 10.1.100.5 activate
>
> no synchronization
>
> exit-address-family
>
> R4 Configuration after BGP SoO
>
> router bgp 65001
>
> no bgp default ipv4-unicast
>
> bgp log-neighbor-changes
>
> neighbor 3.3.3.3 remote-as 65001
>
> neighbor 3.3.3.3 update-source Loopback0
>
> !
>
> address-family vpnv4
>
> neighbor 3.3.3.3 activate
>
> neighbor 3.3.3.3 send-community extended
>
> exit-address-family
>
> !
>
> address-family ipv4 vrf CB
>
> neighbor 10.1.45.5 remote-as 65015
>
> neighbor 10.1.45.5 activate
>
> neighbor 10.1.45.5 as-override
>
> neighbor 10.1.45.5 soo 65015:1
>
> neighbor 10.1.100.5 remote-as 65015
>
> neighbor 10.1.100.5 activate
>
> neighbor 10.1.100.5 soo 65015:1
>
> no synchronization
>
> exit-address-family
>
> Now back to Narbik's configuration after BGP SoO on R4, the results are
> same if I do below configuration
>
> route-map TST permit 10
>
> set extcommunity soo 1:105
>
> ip extcommunity-list 1 permit soo 1:105
>
> route-map TEST deny 10
>
> match extcommunity 1
>
> route-map TEST permit 90
>
> router bgp 65001
>
> no bgp default ipv4-unicast
>
> bgp log-neighbor-changes
>
> neighbor 3.3.3.3 remote-as 65001
>
> neighbor 3.3.3.3 update-source Loopback0
>
> !
>
> address-family vpnv4
>
> neighbor 3.3.3.3 activate
>
> neighbor 3.3.3.3 send-community extended
>
> exit-address-family
>
> !
>
> address-family ipv4 vrf CB
>
> neighbor 10.1.45.5 remote-as 65015
>
> neighbor 10.1.45.5 activate
>
> neighbor 10.1.45.5 as-override
>
> neighbor 10.1.45.5 route-map TST in
>
> neighbor 10.1.45.5 route-map TEST out
>
> neighbor 10.1.100.5 remote-as 65015
>
> neighbor 10.1.100.5 activate
>
> neighbor 10.1.100.5 route-map TST in
>
> neighbor 10.1.100.5 route-map TEST out
>
> no synchronization
>
> exit-address-family
>
> R5 Configuration:
>
> router bgp 65015
> no synchronization
> bgp log-neighbor-changes
> network 5.0.0.0
> network 192.168.5.0
> neighbor 10.1.45.4 remote-as 65001
> neighbor 10.1.100.4 remote-as 65001
> neighbor 10.1.100.4 allowas-in
> no auto-summary
>
>
>
> I'm confused as why I am getting same results in terms on R5 doesn't learn
> it's loopback 5.5.5.5 when we implement configuration in two different ways.
> The first configuration is simple and do the same task and Narbik
> configuration provide same results.
>
> I am sure, if I am missing something. Can anyone please shed some light on
> my ignorance. I apologise if the post is confusing and long, but will be
> highly appreciated, is some please help.
>
> Thanks,
>
> Bilal Hansrod

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Received on Fri Jun 10 2011 - 11:11:22 ART