injecting bgp default route into rip

[johncheung]

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

[mark-obrien]

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

[deilert]

is 100.100.100.1 pingable from router 2

[johncheung]

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

[ruwhite]

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