From: Todd, Douglas M. (DTODD@PARTNERS.ORG)
Date: Wed Feb 27 2008 - 11:12:26 ARST
Hi:
my 2c..
This is expected from what I believe. The use of the default-network allows the
router to send all unknown destinations toward this network. This causes a
recursive lookup on the router, this is the way it works. But the
default-network command works in conjuction with other routing protocols -
CCO:
Cisco IOS software will source the default network with RIP if one of the
following conditions is met:
*The ip default-network command is configured.
*The default-information originate command is configured.
*The default route is learned via another routing protocol or static route and
then redistributed into RIP
This I see as the default network, not the default route..
For rip the default route needs to come from a nother protocol, other wise you
need to have a static route
ip route 0.0.0.0 0.0.0.0 1.1.1.1 and then redistribute that route w/in rip.
If you have eigrp/ospf/bgp sending a default route then you can redistribute
that into rip (and use the default information originate command).
Otherwise, you will just see the default network if the above conditions exist.
CCO:
If dynamic default information is not being passed to the software, candidates
for the default route are specified with the ip default-network global
configuration command. In this usage, the ip default-network command takes an
unconnected network as an argument. If this network appears in the routing table
from any source (dynamic or static), it is flagged as a candidate default route
and is a possible choice as the default route.
If the router has no interface on the default network, but does have a route to
it, it considers this network as a candidate default path. The route candidates
are examined and the best one is chosen, based on administrative distance and
metric. The gateway to the best default path becomes the gateway of last resort.
So,
Create an ospf domain and get a default route advertised into it, then
redistribute it into rip. You will then have a default route.
DMT
________________________________
From: nobody@groupstudy.com on behalf of YourPal
Sent: Tue 2/26/2008 10:14 PM
To: ccielab@groupstudy.com
Subject: Issue advertising default route into RIP using "ip default-network"
Hi Group,
I'm facing a problem advertising a default route into RIP using the "ip
default-network" command. My setup as follows:
R1(s0/0/1)--------
131.108.99.0/24--------(s0/2)R3(s0/3)--------161.44.192.0/24--------(s0/0/1)R2
R1:
!
interface Serial0/0/1
ip address 131.108.99.1 255.255.255.0
clockrate 125000
!
router rip
version 2
network 131.108.0.0
no auto-summary
!
ip classless
!
R2:
!
interface Loopback0
ip address 198.10.1.1 255.255.255.0
!
interface Serial0/0/1
ip address 161.44.192.2 255.255.255.0
clockrate 125000
!
ip classless
!
R3:
!
interface Serial0/2
ip address 131.108.99.3 255.255.255.0
!
interface Serial0/3
ip address 161.44.192.3 255.255.255.0
!
router rip
version 2
network 131.108.0.0
no auto-summary
!
ip default-network 198.10.1.0
ip route 198.10.1.0 255.255.255.0 161.44.192.2
!
ip classless
!
R3#sh ip ro
Gateway of last resort is 161.44.192.2 to network 198.10.1.0
161.44.0.0/24 is subnetted, 1 subnets
C 161.44.192.0 is directly connected, Serial0/3
131.108.0.0/24 is subnetted, 1 subnets
C 131.108.99.0 is directly connected, Serial0/2
S* 198.10.1.0/24 [1/0] via 161.44.192.2
R3#deb ip rip
RIP protocol debugging is on
*Mar 1 07:10:47.535: RIP: sending v2 update to 224.0.0.9 via Serial0/2 (
131.108.99.3)
*Mar 1 07:10:47.535: RIP: build update entries - suppressing null update
R1#sh ip ro
Gateway of last resort is not set
131.108.0.0/24 is subnetted, 1 subnets
C 131.108.99.0 is directly connected, Serial0/0/1
I'm expecting R3 to advertise a default route into RIP as a result of the
"ip default-network" command. However it doesn't. Can anyone tell me what am
I missing in my configuration?
Thank you.
BR,
Emil
This archive was generated by hypermail 2.1.4 : Sat Mar 01 2008 - 16:54:50 ARST