Redistribute EIGRP static routes using a prefix-list and a route-map

In some instances you may have a core switch with a link to a WAN router exchanging routes using a dynamic routing protocol such as EIGRP, static routes to other routers and a default route to the internet firewall. You may not have the ability to run a routing protocol on the other routers so you may find yourself with a load of static IP addresses on the core switch. In order for the branch sites to have full visibility of the entire network we’d need to redistribute the static IP addresses into EIGRP. If we used the command “redistribute statics” on the core switch it would redistribute all static addresses including the default route, which would mean the branch sites would now route ALL traffic back to the central site. Depending on your scenario this may or may not be desired. We can control what subnets are redistributed into EIGRP by the use of a route-map in conjunction with a prefix-list.

I setup this scenario in a lab using GN3 and fully tested before implementing in the production network, I’d suggest you do the same.



Procedure

Before implementing the route map issue the “redistribute static” command on SWI1 and check the routing table on R1. You will notice the gateway of last resort is learnt via EIGRP

router eigrp 10
redistribute static

We want to control what statics we redistribute via EIGRP, so for now stop redistributing statics.

router eigrp 10
no redistribute static

Create a prefix-list called “PERMIT” and specify the routes to be redistributed. You can add more subnets at a later, just create another entry in the prefix list (ensure the sequence number is increased for each new subnet)

ip prefix-list PERMIT seq 10 permit 192.168.100.0/24
ip prefix-list PERMIT seq 20 permit 192.168.110.0/24
ip prefix-list PERMIT seq 30 permit 192.168.120.0/24  

Create a route-map called “PERMITTED-STATICS” and specify permit, then match ip addresses in the previously created prefix-list “PERMIT”. Add a second command to the route-map to “deny” all other (this will stop any route not specified in the route-map from being redistributed in EIGRP).

route-map PERMITTED-STATICS permit 10
match ip address prefix-list PERMIT
route-map PERMITTED-STATICS deny 20  

Modify EIGRP and specify the route-map to use when redistributing statics.

router eigrp 10
redistribute static route-map PERMITTED-STATICS  

Once the route-map is applied confirm the static routes are redistributed and the gateway of last resort is NOT set.


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