Rob, You must be familiar with the path selection process:
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094431.shtml On Sun, Jul 5, 2009 at 8:03 PM, Rob <[email protected]> wrote: > All, > > > > I have never spent a ton of time on BGP in a lab before so before I started > work in the workbook I wanted to play with the different pieces in a simple > setup. Right now I am only dealing with EBGP using the IPexpert lab > setup. R2 and R5 are setup in the same fashion as vol 1 section 11 but > using different BGP AS’s. > > > > The problem I can not figure out is the path selection between R5 and R2. > The both peer up and as you will see below default to go over the serial > interface(150.100.25.0/24) between R2 and R5 for any paths on R1. If I > shutdown that serial interface it falls back to the Frame-relay link. What > I can not figure out is why if prefers the serial link with the network > 150.100.25.0. I attempted to put a weight on the Frame-relay side as show > below, but it still is sending traffic across the 150.100.25.0 network. Why > is this? I assume without the weight statement the choice was made by > lowest ip address. With the weight command I can not figure out at all. I > thought weight won on on networks with multiple paths. > > > > Any help would be great. > > > > > > ----------------------------------------------------- > > R5 > > > > Gateway of last resort is not set > > > > 200.0.0.0/32 is subnetted, 3 subnets > > B 200.0.0.1 [20/0] via 150.100.25.2, 00:03:32 > > B 200.0.0.2 [20/0] via 150.100.25.2, 00:03:32 > > C 200.0.0.5 is directly connected, Loopback1 > > 150.100.0.0/24 is subnetted, 5 subnets > > C 150.100.220.0 is directly connected, FastEthernet0/0 > > C 150.100.221.0 is directly connected, FastEthernet0/1 > > C 150.100.100.0 is directly connected, Serial0/0 > > C 150.100.25.0 is directly connected, Serial0/1 > > B 150.100.12.0 [20/0] via 150.100.25.2, 00:03:33 > > R5-2611XM#sh run | s bgp > > router bgp 135 > > no synchronization > > bgp log-neighbor-changes > > network 150.100.25.0 mask 255.255.255.0 > > network 150.100.100.0 mask 255.255.255.0 > > network 150.100.220.0 mask 255.255.255.0 > > network 150.100.221.0 mask 255.255.255.0 > > network 200.0.0.5 mask 255.255.255.255 > > neighbor 150.100.25.2 remote-as 132 > > neighbor 150.100.100.2 remote-as 132 > > neighbor 150.100.100.2 weight 33000 > > no auto-summary > > R5-2611XM#sh ip bgp > > BGP table version is 506, local router ID is 200.0.0.5 > > 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 > > *> 150.100.12.0/24 150.100.25.2 0 0 132 i > > * 150.100.100.2 0 0 132 i > > * 150.100.25.0/24 150.100.25.2 0 0 132 i > > * 150.100.100.2 0 100 132 i > > *> 0.0.0.0 0 32768 i > > * 150.100.100.0/24 150.100.25.2 0 0 132 i > > * 150.100.100.2 0 0 132 i > > *> 0.0.0.0 0 32768 i > > *> 150.100.220.0/24 0.0.0.0 0 32768 i > > *> 150.100.221.0/24 0.0.0.0 0 32768 i > > *> 200.0.0.1/32 150.100.25.2 0 132 22222 i > > * 150.100.100.2 0 132 22222 i > > *> 200.0.0.2/32 150.100.25.2 0 0 132 i > > * 150.100.100.2 0 0 132 i > > *> 200.0.0.5/32 0.0.0.0 0 32768 i > > > > > > > > -------------------------------------------------------------------- > > R2 > > > > R2_R2621#sh run | b 132 > > router bgp 132 > > no synchronization > > bgp log-neighbor-changes > > network 150.100.12.0 mask 255.255.255.0 > > network 150.100.25.0 mask 255.255.255.0 > > network 150.100.100.0 mask 255.255.255.0 > > network 200.0.0.2 mask 255.255.255.255 > > neighbor 150.100.12.1 remote-as 22222 > > neighbor 150.100.25.5 remote-as 135 > > neighbor 150.100.100.5 remote-as 135 > > no auto-summary > > > > Gateway of last resort is not set > > > > 200.0.0.0/32 is subnetted, 3 subnets > > B 200.0.0.1 [20/0] via 150.100.12.1, 02:06:56 > > C 200.0.0.2 is directly connected, Loopback1 > > B 200.0.0.5 [20/0] via 150.100.25.5, 00:10:09 > > 150.100.0.0/24 is subnetted, 6 subnets > > B 150.100.220.0 [20/0] via 150.100.25.5, 00:10:09 > > B 150.100.221.0 [20/0] via 150.100.25.5, 00:10:09 > > C 150.100.100.0 is directly connected, Serial1/0.256 > > C 150.100.24.0 is directly connected, Serial1/0.24 > > C 150.100.25.0 is directly connected, Serial0/0 > > C 150.100.12.0 is directly connected, FastEthernet0/0 > > R2_R2621#sh ip bgp > > BGP table version is 266, local router ID is 200.0.0.2 > > 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 > > * 150.100.12.0/24 150.100.12.1 0 0 22222 i > > *> 0.0.0.0 0 32768 i > > * 150.100.25.0/24 150.100.25.5 0 0 135 i > > * 150.100.100.5 0 0 135 i > > *> 0.0.0.0 0 32768 i > > * 150.100.100.0/24 150.100.25.5 0 0 135 i > > * 150.100.100.5 0 0 135 i > > *> 0.0.0.0 0 32768 i > > *> 150.100.220.0/24 150.100.25.5 0 0 135 i > > * 150.100.100.5 0 0 135 i > > *> 150.100.221.0/24 150.100.25.5 0 0 135 i > > * 150.100.100.5 0 0 135 i > > *> 200.0.0.1/32 150.100.12.1 0 0 22222 i > > *> 200.0.0.2/32 0.0.0.0 0 32768 i > > *> 200.0.0.5/32 150.100.25.5 0 0 135 i > > * 150.100.100.5 0 0 135 i > > > > > > Checked by AVG - www.avg.com > Version: 8.5.375 / Virus Database: 270.12.94/2207 - Release Date: 07/05/09 > 17:54:00 > > -- Bryan Bartik CCIE #23707 (R&S), CCNP Sr. Support Engineer - IPexpert, Inc. 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