Originating a default route with RIP

From: crl (cisco@xxxxxxxxxxxx)
Date: Thu Mar 01 2001 - 20:21:55 GMT-3


   

The easy solution to this problem is to use a static route. Assume a static
route is not allowed.

eigrp domain rip domain
-------r2----r3----r4----

- r3 is redistributing rip into eigrp 1
- r3 is not redistributing eigrp into rip
- since the rip domain can be likened to a stub network, I'd rather just
originate a default route from r3.
- r3 has a candidate default network from elsewhere in the eigrp domain,
which it selects as its gateway of last resort.

Docs indicate that simply adding the command "default-information originate"
to the RIP process on r3 will advertise a 0.0.0.0/0 route. The docs don't
say that a 0.0.0.0/0 route must already be in the table, but it appears to
be the case. If I add a static default route to r3, there's no problem.

I guess my problem is that from what I understand in the lab static routes
are not allowed. Is there any other way to get a default without using a
static? I've saved previous threads on this topic, and everybody seems to
think RIP will just blindly advertise 0.0.0.0/0 if the def-inf orig command
is configured.

Also, from the perspective of the lab, do static routes that point to null0
"count" in that you're not allowed to configure them unless otherwise
stated? Currently this is a grey area. Will the lab provide the crystal
clear answer to this question?

Configs:
------------------

r3 relevant configs and IP routing table:

!
router eigrp 1
 redistribute rip metric 1000 100 200 10 1500
 passive-interface default
 no passive-interface Serial0
 no passive-interface TokenRing0
 network 12.0.0.0
 no auto-summary
!
router rip
 redistribute eigrp 1
 passive-interface default
 no passive-interface Serial1
 network 12.0.0.0
 default-information originate

Gateway of last resort is 12.12.3.2 to network 192.168.254.0

     12.0.0.0/8 is variably subnetted, 10 subnets, 4 masks
C 12.12.1.0/24 is directly connected, Serial0
D 12.12.2.0/30 [90/2185984] via 12.12.3.2, 01:00:45, TokenRing0
C 12.12.3.0/24 is directly connected, TokenRing0
D 12.12.4.0/28 [90/297728] via 12.12.3.2, 01:00:46, TokenRing0
C 12.12.16.0/24 is directly connected, Serial1
R 12.12.17.0/24 [120/1] via 12.12.16.2, 00:00:19, Serial1
C 12.12.16.2/32 is directly connected, Serial1
D 12.12.32.0/24 [90/2195456] via 12.12.1.1, 01:00:46, Serial0
D 12.12.33.0/24 [90/41536000] via 12.12.1.1, 01:00:46, Serial0
D 12.12.33.2/32 [90/41536000] via 12.12.1.1, 01:00:46, Serial0
D*EX 192.168.254.0/24 [170/176128] via 12.12.3.2, 01:00:46, TokenRing0

-------------------

r4 IP routing table:

Gateway of last resort is not set

     12.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
R 12.12.1.0/24 [120/1] via 12.12.16.1, 00:00:08, Serial0
R 12.12.3.0/24 [120/1] via 12.12.16.1, 00:00:08, Serial0
C 12.12.16.0/24 is directly connected, Serial0
C 12.12.17.0/24 is directly connected, TokenRing0
C 12.12.16.1/32 is directly connected, Serial0



This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:29:17 GMT-3