BGP Advertising

[Norman123]

Hello,

Need some help on the below code. we have 2 bgp path ( primary and backup) and i configure 1 subnet to be routed through main path and the rest 3 subnets through backup.

on the backup i have the 3 subnet primary and the first subnet as backup 

router bgp 334

no bgp default ipv4-unicast
neighbor 192.169.2.1 remote-as 444
neighbor 192.169.2.1 description ISP-B
neighbor 192.169.1.1 remote-as 222
neighbor 192.169.1.1 description ISP-A
neighbor 192.169.1.1 ebgp-multihop 5


!
address-family ipv4
network 10.0.0.0 mask 255.255.255.0
network 20.0.0.0 mask 255.255.255.0
network 30.0.0.0 mask 255.255.255.0
network 40.0.0.0 mask 255.255.255.0
neighbor 192.169.2.1 activate
neighbor 192.169.2.1 next-hop-self
neighbor 192.169.2.1 soft-reconfiguration inbound
neighbor 192.169.2.1 prefix-list ISPBIn in
neighbor 192.169.2.1 route-map ISPBOut out
neighbor 192.169.1.1 activate
neighbor 192.169.1.1 next-hop-self
neighbor 192.169.1.1 weight 500
neighbor 192.169.1.1 soft-reconfiguration inbound
neighbor 192.169.1.1 route-map ISPAOut out
maximum-paths 4
exit-address-family
!

ip prefix-list ISPBIn seq 10 permit 0.0.0.0/0
ip prefix-list ISPBIn seq 100 deny 0.0.0.0/0 le 32

route-map ISPBOut permit 20
match ip address prefix-list ISPBPrimary
set origin incomplete
!
route-map ISPBOut permit 30
match ip address prefix-list ISPBBackup
set origin incomplete
set as-path prepend 334 334 334 334

route-map ISPAOut permit 10
match ip address prefix-list ISPAPrimary
set origin incomplete

route-map ISPAOut permit 20
match ip address prefix-list ISPABackup
set origin incomplete
set as-path prepend 334 334 334 334

ip prefix-list ISPBPrimary seq 20 permit 20.0.0.0/24
ip prefix-list ISPBPrimary seq 30 permit 30.0.0.0/24
ip prefix-list ISPBPrimary seq 40 permit 40.0.0.0/24
ip prefix-list ISPBPrimary seq 100 deny 0.0.0.0/0 le 32

ip prefix-list ISPBBackup seq 50 permit 10.0.0.0/24
ip prefix-list ISPBBackup seq 100 deny 0.0.0.0/0 le 32

ip prefix-list ISPAPrimary seq 5 permit 10.0.0.0/24
ip prefix-list ISPAPrimary seq 100 deny 0.0.0.0/0 le 32

ip prefix-list ISPABackup seq 8 permit 20.0.0.0/24
ip prefix-list ISPABackup seq 9 permit 30.0.0.0/24
ip prefix-list ISPABackup seq 10 permit 40.0.0.0/24
ip prefix-list ISPABackup seq 100 deny 0.0.0.0/0 le 32

________________________________________________

Its not matching 100% . 

[MHM Cisco World]

This not clear 

Route these subnet need route-map IN and you receive this prefix' am I correct?

MHM

[Norman123]

adding the below in the routes.

ip route 10.0.0.0 255.255.255.0 Null0 252
ip route 20.0.0.0 255.255.255.0 Null0 252
ip route 30.0.0.0 255.255.255.0 Null0 252
ip route 40.0.0.0 255.255.255.0 Null0 252

Want to set the first subnet (10.0.0.0) to be on main path uplink and downlink . while the others on the backup path and vice versa

Can you inform me what am doing wrong in the configuration above ?

[MHM Cisco World]

Sorry' maybe other help you in your task' 

But what you want to achieve can not done with only these step.

The prefix you mention is send via primary and backup' and this effect traffic INBOUND to these subnet' for traffic OUTBOUND you need route-map "pbr" since I think receive default route from both ISP.

Thanks a lot 

Have a nice weekend 

MHM

[paul driver]

Hello
See attached for posible solution-  

[Norman123]

Hello Paul

As i can see in this solution, the first subnet 10.0.0.0/24 will not be advertised the main path.

Regards,