From: MADMAN (dmadlan@xxxxxxxxx)
Date: Tue Apr 23 2002 - 14:33:10 GMT-3
Here is a straight forward explanation...
http://www.cisco.com/warp/public/459/bgpfaq_5816.shtml#19
Dave
Alex Paulino wrote:
>
> Hi folks, sorry about this simple doubt, but, i just wanna some tips about ib
gp over synchronization environment.
>
>
>
> R8 peer with R2 and receives: 200.2.2.0/24 from AS 2.
>
> R7 peering R8 using synchronzation (AS87). R7 receives this route and place i
t as valid route because in the
>
> R8 i have redistributed BGP command under ospf process.
> As ospf has Administrative distance equal 110, and iBGP equal 200, this route
never comes up from BGP in R7, if i put this route with administrative route >
200 in OSPF process, bgp cannot to put this route in your routing table.
>
> I have tried to configure R7 to set distance to this route to 220 under osp p
rocess. After to do this, the R7 has the follow entry in osp table:
>
> R7#sh ip route 200.2.2.0
> Routing entry for 200.2.2.0/24
> Known via "ospf 10", distance 220, metric 49
> ...
> !
> Note that the route now has the distance 220 and this routestill is over ospf
and it is not valid from BGP table:
>
> R7#sh ip bgp
> BGP table version is 42, local router ID is 200.87.87.1
> Status codes: s suppressed, d damped, h history, * valid, > best, i - interna
l
> Origin codes: i - IGP, e - EGP, ? - incomplete
> Network Next Hop Metric LocPrf Weight Path
> * i200.2.2.0 138.1.8.8 0 100 0 2 i
> *> 200.87.87.0 0.0.0.0 0 32768 i
>
> Does exist some solution for to R7 places this route into bgp table or this
never will happen? Which does i must to care in this situation?
>
>
> thanks in advance.
> alex
> Follow my configuration...
> R8)
> router ospf 10
> redistribute bgp 87 subnets
> network 138.1.0.0 0.0.255.255 area 0
> !
> router bgp 87
> neighbor 138.1.2.2 remote-as 2
> neighbor 138.1.2.2 ebgp-multihop 15
> neighbor 138.1.2.2 update-source Loopback0
> neighbor 138.1.2.2 soft-reconfiguration inbound
> neighbor 138.1.7.7 remote-as 87
> neighbor 138.1.7.7 update-source Loopback0
> neighbor 138.1.7.7 next-hop-self
> neighbor 138.1.7.7 soft-reconfiguration inbound
> !
> R7)
> router ospf 10
> redistribute bgp 87 subnets
> network 138.1.0.0 0.0.255.255 area 0
> !
> router bgp 87
> neighbor 138.1.8.8 remote-as 87
> neighbor 138.1.8.8 update-source Loopback0
> neighbor 138.1.8.8 next-hop-self
> neighbor 138.1.8.8 soft-reconfiguration inbound
> !
> Follow the shows without change the Administrative distance to 220 in R7 to 2
00.2.2.0 route:
> R7#sh ip bgp
> BGP table version is 67, local router ID is 200.87.87.1
> Status codes: s suppressed, d damped, h history, * valid, > best, i - interna
l
> Origin codes: i - IGP, e - EGP, ? - incomplete
> Network Next Hop Metric LocPrf Weight Path
> *>i200.2.2.0 138.1.8.8 0 100 0 2 i
> *> 200.87.87.0 0.0.0.0 0 32768 i
> !
> R7#sh ip route 200.2.2.0
> Routing entry for 200.2.2.0/24
> Known via "ospf 10", distance 110, metric 1
> Tag 2, type extern 2, forward metric 48
> Redistributing via ospf 10
> Last update from 138.1.123.8 on Serial0/0.1, 00:16:12 ago
> Routing Descriptor Blocks:
> * 138.1.123.8, from 138.1.8.8, 00:16:12 ago, via Serial0/0.1
> Route metric is 1, traffic share count is 1
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