03-01-2007 08:16 AM - edited 03-03-2019 03:59 PM
Hello,
Let's say i have 4 routers connected.
10.10.10.0 /24 and 12.12.12.1/24 is on Router # 1 which when i advertise to Router # 2, I only want Router # 2 to advertise 10.10.10.0/24 to Router # 3 and the rest of the networks which it learns from Router #1 sends it to other Routers or to different neighbors. My main goal is to filter the networks so it doesn't get injected into other neighbors and only sends to particular neighbors by using access-list on tags
One way of doing it is if on Router # 1, i create a
route-map set_tagging permit
set tag 5
R# 1
router bgp xxx
network 10.10.10.0 mask 255.255.255.0 route-map set_ tagging
Now, on Router # 2 when it learns about 10.10.10.0/24, depending on the access-list it forwards only to particular neighbor.
Is there any other way of filtering networks coming in without using the route-map tagging on network...Any idea, not sure if i am clear on this one or not.
Regards,
Hassan
03-01-2007 08:45 AM
yes you can filter the network using the Prefix list, as-path accesslist, distribute list... etc...
using prefix list you can allow and deny perticular prefix from advertise to other peer or to receive the update from other peer...
but using AS-Path access-list you can allow or deny to receive route from perticular AS...
regards
Devang
03-01-2007 08:49 AM
go to this link:http://cisco.com/univercd/cc/td/doc/cisintwk/ics/icsbgp4.htm
it will clear your all the issue...
regards
Devang
03-01-2007 08:54 AM
Hassan,
BGP can carry community attributes that would allow you to do the same thing other routing protocols would do using tags. BGP doesn't carry tags in its updates.
You could attach a given community to a routing update on one router and filter based on that same community on another router.
Hope this helps,
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