08-13-2003 09:44 PM - edited 03-02-2019 09:35 AM
i am reading sam halabi' s excellent book called "internet routing architectures"...on p. 404, it says that for a bgp learnt 0/0 default route "no redistribution was necessary to inject the BGP default into RIP"...i tried a simple lab test and found that i had to use the redistribute command under rip and include bgp redistribute-internal command under bgp to have the 0/0 default route injected into rip...has anyone been able to inject the bgp learnt 0/0 default route into an igp like rip without using the redistribute command as per halabi? Following are my show running-configs and show ip route commands for the 2 lab routers(ios 12.1) i am using:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
!
hostname r1
!
interface Loopback100
ip address 100.100.100.1 255.255.255.0
!
interface Serial0
ip address 192.168.12.1 255.255.255.0
encapsulation frame-relay
frame-relay map ip 192.168.12.2 809 broadcast
!
router rip
redistribute bgp 1
network 192.168.12.0
default-metric 2
!
router bgp 1
no synchronization
bgp redistribute-internal
bgp log-neighbor-changes
network 0.0.0.0
!
ip route 0.0.0.0 0.0.0.0 Loopback100
end
r1#sh ip route
Gateway of last resort is 0.0.0.0 to network 0.0.0.0
C 192.168.12.0/24 is directly connected, Serial0
100.0.0.0/24 is subnetted, 1 subnets
C 100.100.100.0 is directly connected, Lo100
S* 0.0.0.0/0 is directly connected, Lo100
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
hostname r2
!
interface Serial0
ip address 192.168.12.2 255.255.255.0
encapsulation frame-relay
frame-relay map ip 192.168.12.1 908 broadcast
!
router rip
network 192.168.12.0
!
r2#sh ip route
Gateway of last resort is 192.168.12.1 to network 0.0.0.0
C 192.168.12.0/24 is directly connected, Se0
R* 0.0.0.0/0 [120/2] via 192.168.12.1, 00:00:06,Se0
Thanks
john
08-14-2003 03:14 AM
John,
It doesn't look as though r1 is learning the default routed via BGP. It is learning it as being a connected network, via your static route pointing it to the loopback interface. To see if RIP does learn of the default via BGP without redistribution, you need to set up a BGP neighbor for r1, and have that neighbor advertise the default, then see if r2 learns the route via RIP.
HTH
Mark
08-14-2003 04:57 AM
is 100.100.100.1 pingable from router 2
08-14-2003 05:19 AM
yes it is...
r2>sh ip route
Gateway of last resort is 192.168.12.1 to network 0.0.0.0
C 192.168.12.0/24 is directly connected, Se0
R* 0.0.0.0/0 [120/2] via 192.168.12.1, 00:00:23,Se0
r2>ping 100.100.100.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 100.100.100.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 44/45/48 ms
Sorry i think i have made myself a little unclear...the problem isn't that i can't reach the default network...the problem is that as per halabi i shouldn't have to redistribute the bgp learnt 0/0 default route into rip...its supposed to happen "magically"...essentially i would like to know if anybody has been able to implement the injection of the bgp learnt 0/0 default route into rip as per halabi(ie no additional ip route commands//no default-information originate command under rip//no redistribute command under rip)
thanks
john
08-15-2003 05:04 AM
This was, once upon a time, true, but when the RIP rewrite was done, probably two years back (?), this code was taken out. If you can do a "show ip rip database," the default route shouldn't be redistributed into RIP automatically.
Russ.W
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