Single Interface with Multiple PBR Rules

As an alternative to a GRE tunnel for each VIP, you could configure multiple Policy Based Routing (PBR) rules. This configuration might be appropriate if you have multiple interfaces to your service providers on a single Cisco GSR router with no GRE capability, for example.

In this system, four interfaces have been configured on the GSR:

• interface s0 connects to provider_1
• interface s1 connects to provider_2
• interface s2 connects to provider_3
• traffic from the three USTAT VIPs arrive on interface GigabitEthernet3/0/0

To make the system work, you need to configure three access lists on the GSR, one for each USTAT VIP:

access-list 188 permit ip host 172.25.5.1 any
 
access-list 188 deny ip any any
 

 
access-list 189 permit ip host 172.25.5.2 any
 
access-list 189 deny ip any any
 

 
access-list 190 permit ip host 172.25.5.3 any
 
access-list 190 deny ip any any
 

 

Then, create a route map (named USTATs for this example):

route-map USTATs permit 10
 
match ip address 188 
 
set ip next-hop 172.30.100.33
 

 
route-map USTATs permit 20
 
match ip address 189 
 
set ip next-hop 172.29.100.33
 

 
route-map USTATs permit 30
 
match ip address 190 
 
set ip next-hop 172.28.100.1
 

 

Finally, enable the policies on the router:

interface GigabitEthernet3/0/0
 
ip policy route-map USTATs in