EIGRP default router propagation

sqambera · ‎03-31-2007

Hi,

I am doing the following configuration on my router in order to propagate a default route from itself onto the neighbour router.

(conf)#router eigrp 1

(config-router)#default-information out

(config-router)#network 10.1.1.0 0.0.0.255

(config-router)#no auto-summary

whereas on the neighbour router (where I want to get the default route) following configuration has been done:

(conf)#router eigrp 1

(config-router)#network 10.1.1.0 0.0.0.255

(config-router)#default-information in

(config-router)#no auto-summary

EIGRP adjency has already been created between the two routers but I am unable to get a default route through eigrp. Please help. Thanks.

royalblues · ‎03-31-2007

Friend,

You do not need the default-information command to propogate a default route in EIGRP.

Add a default route on the router one.

Redistribute this static route in EIGRP and the neighbor should be able to see it

ip route 0.0.0.0 0.0.0.0

conf)#router eigrp 1

(config-router)#redistribute static

(config-router)#network 10.1.1.0 0.0.0.255

(config-router)#no auto-summary

The default-information-originate is used in OSPF

HTH, rate if it does

Narayan

sqambera · ‎03-31-2007

Thanks for the reply. Won't this redistribute all the static routes of my router into EIGRP? What can I do to only redistribute the default route?

Also, if for example ospf is also running between the two routers, will a default route being redistributed into eigrp and propagated to neighbour will take place of OSPF default route, that has been generated by "default-information-orignate" in ospf configuration and I can see it on my second router with *E2?

Jon Marshall · ‎03-31-2007

Hi

Yes the "redistribute static" command will redistribute all your static routes defined on that router into EIGRP.

If you don't want that you can use a route-map to allow only those static routes you want into EIGRP eg:

router eigrp 20

redistribute static route_map default_only

access-list 1 permit 0.0.0.0

route-map default_only permit 10

match ip address 1

HTH

Jon

rajinikanth · ‎03-31-2007

Hi ,

You can also use this method on your router1

to propagate default route.

(config-router)#default-network 10.1.1.0

now your router2 sees a default network with next hop of Router1

the other method is already been told by royalblues

Hope this helps

RAJ

flashsplash · ‎04-02-2007

the method which RAJ is talking about is indeed another option but it's very hard to get is work right with IGRP & EIGRP

u can propagate default routes by 3 ways

1. by using ip route [but u need to use the redistrubute command when making use of the ip route command. [!!!can' t use IGRP with this command]

2. By using the default-network command [but u need to add the network with as classfull cuase this is a classfull command. [!!!can't use OSPF & ISIS with this command]

3. By using the default-gateway commmand [when making use of this command ip routing must be disabled

ciao flash

sqambera · ‎04-03-2007

What about if we do the following:

(config)#router eigrp 100

(config-router)network 10.0.0.0

(config)#int s0/0

(config-if)#ip add 10.1.1.1 255.255.255.0

(config-if)#ip summary-address eigrp 100 0.0.0.0 0.0.0.0

Does it also has the same effect of propagating the default route or does it make any difference?

Thanks.

rajinikanth · ‎04-03-2007

Hi,

You are correct, this is also a method to propagate default route via summary address command.

HTH

Raj

walleyewiz · ‎04-09-2007

This is a good way to do it because you suppress all routes. Make sure you put admin distance on summary statement or you could black hole traffic. Summary route has admin distance of 5, if you are learning a default from some other source for the upstream traffic dynamically, you could send traffic to null 0. I always put a 250 just to make sure:

ip summary-address eigrp 100 0.0.0.0 0.0.0.0 250