IRDP not work?

[waimen]

Hi All,

I use the following topology to test IRDP:

..............R3

................|

R1--R2-----R4--R5

.........|_____|

R1,R2,R4 and R5 use ISIS and there is route to get each other. R3 use "no ip routing " to disable routing. In the interfaces of R2 and R4 that with the same vlan of R3, I issue "ip irdp " command in the interface. But in R3 I can not get to R1 and R5. Is there anything I done wrong? Can any body tell me? Thank You!

Waimen

[mark-obrien]

Waimen,

When you issued the "no ip routing command", you not only disable routing protocols, but you disable all IP capability in the router. IRDP is a function of ICMP, which is part of IP. Therefore, when you disabled IP routing you disabled IRDP (which I assume is IP Router Discovery Protocol) and any ability for R3 to reach other routers on an IP basis.

Mark

[waimen]

Hi Mark,

I enable routing again and got the same result. And my understanding is IRDP is a method that let the hosts that have no default gateway to " get " their default gateway. So must I also enable the routing in R3 ( I disable routing in R3 to make it like a normal PC)? If my understanding is wrong or their is any information about IRDP, please tell me. Thanks alot!!

Waimen