From: Philip Guo (guo6688@xxxxxxxxxxx)
Date: Tue May 22 2001 - 01:32:38 GMT-3
I guess There is no IGP connection between these three routers.
For example, R2 can not reach 192.168.20.49/28 internally. So it can not
select as best route.
Philip
>From: "zhutong" <zhutong@ronghai.com.cn>
>Reply-To: "zhutong" <zhutong@ronghai.com.cn>
>To: "CCIE Mailist" <ccielab@groupstudy.com>
>Subject: BGP Route Selection
>Date: Tue, 22 May 2001 12:04:18 +0800
>
>I have three routers, R1 is in AS 1, R2 & R3 in AS100, following are there
>configuratons,
>and "show ip bgp" for R2 and R3, it seems not using the best path, why?
>
>R1
>========================================
>interface Loopback0
> ip address 1.1.1.1 255.255.255.0
>interface Serial1/0
> ip address 192.168.20.17 255.255.255.240
>interface Serial1/1
> ip address 192.168.20.49 255.255.255.240
>router bgp 1
> network 1.0.0.0
> neighbor 192.168.20.18 remote-as 100
> neighbor 192.168.20.50 remote-as 100
>
>R2
>========================================
>interface FastEthernet0/0
> ip address 192.168.20.65 255.255.255.240
>interface Serial1/0
> ip address 192.168.20.18 255.255.255.240
>router bgp 100
> bgp default local-preference 200
> neighbor 192.168.20.17 remote-as 1
> neighbor 192.168.20.17 weight 1000
> neighbor 192.168.20.66 remote-as 100
> neighbor 192.168.20.66 weight 3000
>
>R3
>========================================
>interface FastEthernet0/0
> ip address 192.168.20.66 255.255.255.240
>interface Serial1/0
> ip address 192.168.20.50 255.255.255.240
>router bgp 100
> bgp default local-preference 300
> neighbor 192.168.20.49 remote-as 1
> neighbor 192.168.20.65 remote-as 100
>
>here are "show ip bgp" output
>R1
>-----------------------------------------------------------------
> Network Next Hop Metric LocPrf Weight Path
>*> 1.0.0.0 0.0.0.0 0 32768 i
>
>R2
>-----------------------------------------------------------------
> Network Next Hop Metric LocPrf Weight Path
>*> 1.0.0.0 192.168.20.17 0 1000 1 i
>* i 192.168.20.49 0 300 3000 1 i
>
>R3
>-----------------------------------------------------------------
> Network Next Hop Metric LocPrf Weight Path
>* i1.0.0.0 192.168.20.17 0 200 0 1 i
>*> 192.168.20.49 0 0 1 i
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