05-14-2007 09:11 AM - edited 03-03-2019 04:58 PM
Dear Sir,
I config the router with BGP and and try to announce the provider A routes. What I want to do is that
1. announce the 192.68.83.0 to provider A with longer as-path
2. annouce the 192.68.80.0, 192.68.81.0 and 192.68.82.0 routes to proiders with normal as-path
3. announce the routes that from my AS number only
4. deny all routes which is NOT from my AS
there are two setting, do both of them can meeting this requirement? which one is better? Please advices. Thanks
Best regards
CM Leung
------- router config ----
access-list 40 permit 192.68.83.0 0.0.0.255
!
access-list 50 permit 192.68.80.0 0.0.0.255
access-list 50 permit 192.68.81.0 0.0.0.255
access-list 50 permit 192.68.82.0 0.0.0.255
ip as-path access-list 100 permit ^$
!
ip as-path access-list 200 permit ^$
ip as-path access-list 210 deny .*
------ setting A -----
!
route-map Set_ASN_provider_a permit 10
match ip address 40
set as-path prepend 235 235 235 235 235 235
!
route-map Set_ASN_provider_a permit 20
match ip address 50
!
route-map Set_ASN_provider_a permit 30
match as-path 200
!
!
route-map Set_ASN_provider_a deny 40
!
---setting B ---
route-map Set_ASN_provider_a permit 10
match ip address 40
set as-path prepend 235 235 235 235 235 235
!
route-map Set_ASN_provider_a permit 20
match ip address 50
!
route-map Set_ASN_provider_a permit 30
match as-path 200
!
!
route-map Set_ASN_provider_a permit 40
match as-path 210
!
Solved! Go to Solution.
05-17-2007 10:23 AM
This will do it. You could simplify the inbound route-map a bit by removing the as-path list to match the first AS, as this first AS in the AS path will always be the AS of the provider. You can also remove the statement where you set the local-pref to 200 and let it default to 100, which is also less than the 300 on the other side.
route-map SetLocalPref_provider_a permit 10
set local-preference 300
!
route-map SetLocalPref_provider_b permit 10
match ip address 35
set local-preference 350
route-map SetLocalPref_provider_b permit 20
Hope this helps,
05-14-2007 10:36 AM
Hi,
Without adding any route-map statements after the
"route-map Set_ASN_provider_a permit 30
match as-path 200 "
The route-map will deny any routes that didn't match the above statements implicitly by default without the need to add any statement to explicit deny.
HTH, please do rate all helpful replies,
Mohammed Mahmoud.
05-17-2007 07:45 AM
Dear Sir,
following is the full config of bgp setting. we would like "202.43.220.0" traffic go provider B, other than that, go second provider. Any comments on it?
Best regards
CM Leung
----
router bgp 38
bgp log-neighbor-changes
!
! provider_a
neighbor 192.68.1.1 remote-as 1111
neighbor 192.68.1.1 description connect to provider_a bgp
neighbor 192.68.1.1 version 4
!
! provider_b
neighbor 192.68.2.2 remote-as 2222
neighbor 192.68.2.2 description connect to provider_b
neighbor 192.68.2.2 version 4
!
!
address-family ipv4
neighbor 192.68.1.1 activate
neighbor 192.68.1.1 soft-reconfiguration inbound
neighbor 192.68.1.1 route-map SetLocalPref_provider_a in
neighbor 192.68.1.1 route-map Set_ASN_provider_a out
!
neighbor 192.68.2.2 activate
neighbor 192.68.2.2 soft-reconfiguration inbound
neighbor 192.68.2.2 route-map SetLocalPref_provider_b in
neighbor 192.68.2.2 route-map Set_ASN_provider_b out
!
no auto-summary
no synchronization
network 172.16.180.0
network 172.16.181.0
network 172.16.182.0
network 172.16.183.0
exit-address-family
!
!
ip as-path access-list 100 permit ^$
!
!announce the route to provider_a
ip as-path access-list 200 permit ^$
!
ip as-path access-list 20 permit ^2222_
ip as-path access-list 10 permit ^1111_
!
!
access-list 35 permit 202.43.220.0 0.0.0.255
!
access-list 40 permit 172.16.183.0 0.0.0.255
!
access-list 50 permit 172.16.180.0 0.0.0.255
access-list 50 permit 172.16.181.0 0.0.0.255
access-list 50 permit 172.16.182.0 0.0.0.255
!
!
!
route-map SetLocalPref_provider_a permit 10
match as-path 10
set local-preference 300
!
route-map SetLocalPref_provider_a permit 20
!
!
!
route-map SetLocalPref_provider_b permit 10
match ip address 35
set local-preference 350
!
!
route-map SetLocalPref_provider_b permit 20
match as-path 20
set local-preference 200
!
route-map SetLocalPref_provider_b permit 30
!
!
route-map Set_ASN_provider_a permit 10
match ip address 40
set as-path prepend 38 38 38 38 38 38
!
route-map Set_ASN_provider_a permit 20
match ip address 50
!
route-map Set_ASN_provider_a permit 30
match as-path 200
!
!
!
!
route-map Set_ASN_provider_b permit 10
match ip address 40
!
route-map Set_ASN_provider_b permit 20
match ip address 50
set as-path prepend 38 38 38 38 38 38
!
route-map Set_ASN_provider_b permit 30
match as-path 100
!
-----
05-17-2007 10:23 AM
This will do it. You could simplify the inbound route-map a bit by removing the as-path list to match the first AS, as this first AS in the AS path will always be the AS of the provider. You can also remove the statement where you set the local-pref to 200 and let it default to 100, which is also less than the 300 on the other side.
route-map SetLocalPref_provider_a permit 10
set local-preference 300
!
route-map SetLocalPref_provider_b permit 10
match ip address 35
set local-preference 350
route-map SetLocalPref_provider_b permit 20
Hope this helps,
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