Null route advertized over EIGRP

[s.kanth]

Hi All,

Topology : R1 --P2P(EIGRP)--- R2 ---MPLS(BGP)---R3

We had a strange issue yesterday, Null router was added in R1 router for below network

<<<ip route 10.25.1.100 255.255.255.255 null0>>

This null route got advertized to R2 and from R2 to R3 . we have EIGRP-BGP redistribution on R3.

Doubts :

1. why null router got advertized to R2 ,though there was no registribution configured on R1.
2. it might got advertized to R2 ,because we have network state 10.0.0.0/8 on R1. due to which it got advertize.. why ?

Please help me how it got advertized to R2.

Thanks

- Sri

[paul driver]

Hello

You are correct about you assumption -

The host route to null  and the advertised network are in the same subnet range, so this WILL be advertised to its eigrp peer of R2.

res

Paul

[s.kanth]

Hi Paul,

So "NULL" route got advertized ,because it matches with network statement...

can you please share the doc/link about NULL route , if you have.

Thanks

Sri