hi
when i opened the topology file it just came with the peer group lab.
Can you check the file?
BGP Attribute AS Path Ignore
Scenario:
You are responsible for a International network. All routers are connected through BGP. One of the network administrators in NewDelhi configure AS Path prepending for their AS so Paris will send all traffic through Sydney. You heard about a hidden option to ignore AS Path information, maybe this is just what you need...
Goal:
- All IP addresses have been preconfigured for you as specified in the topology picture.
- Configure EBGP between all the ASes.
- Advertise the loopback0 interface on router Barcelona in BGP.
- Router Paris should have two paths to reach network 1.1.1.0 /24.
- Configure AS Path prepending on router NewDelhi so router Paris sends all traffic to network 1.1.1.0 /24 through router Sydney.
- Configure router Paris to ignore the added ASes so it will send traffic for network 1.1.1.0 /24 to router NewDelhi. Don't use any of the other BGP attributes.
IOS:
c3640-jk9o3s-mz.124-16.bin
Topology:
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Comments (5)
-
breland_101 2012-02-09 05:03:33I cannot get the follow as-path ignore command to work
R2(config-router)#bgp bestpath ?
compare-routerid Compare router-id for identical EBGP paths
cost-community cost community
med MED attribute
Cisco IOS Software, 3600 Software (C3640-JK9O3S-M), Version 12.4(16a), RELEASE SOFTWARE (fc2)
Any idea why this might be?
-
alkgrig 2012-02-28 21:55:22Just try the command, it will work even if it is not shown.
"bgp bestpath as-path ignore"
you will then see it in the running config.
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Bougrine 2012-03-06 00:44:27Hi,
To complete this lab, use the same topology as "BGP Attribute Router ID"
1) NewDelhi ---Router-ID = 2.2.2.2
neighbor 192.168.23.3 route-map as-prepend out ---- towards Paris
route-map as-prepend permit 10
set as-path prepend 2 2 2
2)
bgp bestpath as-path ignore ------------ just past the command even it is showing up
bgp bestpath compare-routerid
based on AS-path lenght the Sydney should be the prefered path, but with " ingore command" Paris will prefer Newdelhi as it has a lower-ID ( 2.2.2.2)
!
Paris#sh ip bgp 1.1.1.0
BGP routing table entry for 1.1.1.0/24, version 2
Paths: (2 available, best #2, table Default-IP-Routing-Table)
Advertised to update-groups:
1
4 1
192.168.34.4 from 192.168.34.4 (4.4.4.4)
Origin IGP, localpref 100, valid, external
2 2 2 2 1
192.168.23.2 from 192.168.23.2 (2.2.2.2)
Origin IGP, localpref 100, valid, external, best
Paris#
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Bougrine 2012-03-06 00:46:50
!!! Rectifictaion!!!
2) Paris config
bgp bestpath as-path ignore ------------ just past the command even it is NOT showing up with ? mark