05-08-2007 07:05 PM - edited 03-03-2019 04:53 PM
Dear Sir,
we config the multi-homed setting on 7301 router. there are two providers (provider A and providers B). We also get 4 class C ip address from APNIC. (e.g. 192.100.4.0/22). we would like to achieve following features:
192.100.4.0/24
192.100.5.0/24
192.100.6.0/24
about networks go the provider A first (inbound and out bound, if provider A down, it goes to provider B)
192.100.7.0/24
about network go the provider B first (inbound and out bound, if provider B down, it goes to provider A)
the current setting is following:
--- provider A setting ---
nei 202.100.1.1 remote-as 111
nei 202.100.1.1 version 4
address-family ipv4
neighbor 202.100.1.1 activate
neighbor 202.100.1.1 soft-reconfiguration inbound
neighbor 202.100.1.1 route-map SetLocalPref_A in
neighbor 202.100.1.1 filter-list 200 out
no auto-summary
no synchronization
network 192.100.4.0
network 192.100.5.0
network 192.100.6.0
network 192.100.7.0
exit-address-family
ip as-path access-list 10 permit ^111_
ip as-path access-list 200 permit ^$
route-map SetLocalPref_A permit 10
match as-path 10
set local-preference 300
!
route-map SetLocalPref_A permit 20
-------
--- provider B setting ---
nei 202.100.2.2 remote-as 222
nei 202.100.2.2 version 4
address-family ipv4
neighbor 202.100.2.2 activate
neighbor 202.100.2.2 soft-reconfiguration inbound
neighbor 202.100.2.2 route-map SetLocalPref_B in
neighbor 202.100.2.2 filter-list 100 out
ip as-path access-list 20 permit ^222_
ip as-path access-list 100 permit ^$
route-map SetLocalPref_B permit 10
match as-path 20
set local-preference 200
!
route-map SetLocalPref_B permit 20
------
Could you kindly guide me to config the bgp? Thanks
Best regards
CM Leung
05-08-2007 10:52 PM
05-09-2007 05:28 AM
Dear Sir,
following is the config we modify. detail is following:
we find that we cannot announce the route to providers. the proivder that we send 10000 routes to them, so they stop the bgp session.
currently, we have one router connect with two ISPs. there is no ibgp config with other router.
It would be greatful that you point out what setting incorrect so that I can correct it. (or any suggestion is appreciated)
---- router config
router bgp 10
bgp log-neighbor-changes
!
! provider_a
neighbor 202.100.1.1 remote-as 111
neighbor 202.100.1.1 description connect to provider_a bgp
neighbor 202.100.1.1 version 4
!
! provider_b
neighbor 202.100.2.2 remote-as 222
neighbor 202.100.2.2 description connect to provider_b
neighbor 202.100.2.2 version 4
!
!
address-family ipv4
neighbor 202.100.1.1 activate
neighbor 202.100.1.1 soft-reconfiguration inbound
neighbor 202.100.1.1 route-map SetLocalPref_provider_a in
neighbor 202.100.1.1 route-map Set_ASN_provider_a out
!
neighbor 202.100.2.2 activate
neighbor 202.100.2.2 soft-reconfiguration inbound
neighbor 202.100.2.2 route-map SetLocalPref_provider_b in
neighbor 202.100.2.2 route-map Set_ASN_provider_b out
!
no auto-summary
no synchronization
network 192.100.4.0
network 192.100.5.0
network 192.100.6.0
network 192.100.7.0
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 ^222_
ip as-path access-list 10 permit ^111_
!
!
access-list 35 permit 202.43.220.0 0.0.0.255
!
access-list 40 permit 192.100.7.0 0.0.0.255
access-list 50 permit 192.100.4.0 0.0.0.255
access-list 50 permit 192.100.5.0 0.0.0.255
access-list 50 permit 192.100.6.0 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 40
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 10 10 10 10 10 10 10
!
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
!
!
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 10 10 10 10 10 10 10
!
route-map Set_ASN_provider_b permit 30
match as-path 100
!
!
route-map Set_ASN_provider_b permit 40
----
05-09-2007 05:49 AM
Hi again,
Yes, you must make sure that you only send
your own summarized addresses to your provider. issue the cmd:
sh ip bgp neighbors 1.1.1.1 advertised-routes
On your outgoing policy you do not need to have this:
!
route-map Set_ASN_provider_a permit 30
match as-path 200
!
!
and this:
!
route-map Set_ASN_provider_b permit 30
match as-path 100
!
And you only need to prepend with one AS not 10 10 10 10.....
HTH, rate if it does.
BR,
Bjornarsb
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