[c-nsp] Preference: Advertised route vs Default static.

[Oliver Boehmer (oboehmer)]

Gangasagar Amula <> wrote on Tuesday, April 05, 2005 3:53 PM:

> Dear All,
> We have hierarchical network.For e.g as below....
>                              A
>                 B                          C
>      D               E                F          G
> 
> ( A is root, is connected to B and C.
> B inturn is connected to D and E.  ///// C is connected to F and
> G///// 
> 
> Now if I am advertising default route from "A" through EIGRP ( thro'
> ip summary-address....) on the interface connected to "b" and
> "C".(Normally such summarisation take AD as "5".) And if I give a
> static default route on "B" with AD as "5" as below  
> ip route 0.0.0.0 0.0.0.0 (ip addr. of the int. of "A" connected to
> "B") 5( same AD as of above) 
> 
> If this is the case, what will be prefered...static route or default
> route advertise by eigrp. 

The static route on B will be preferred since it has a lower distance
(5) compared to the EIGRP-learned default with its distance of 90.
Distance only has local significance, so "ip summary-address ..... 5"
installs the summary with AD 5 at router A only, router B sees it with
EIGRP's AD of 90.

> Will "D" and "E" will be able to learn their default route....

No. Since B doesn't know the 0/0 via EIGRP, it doesn't propagate it to
its neighbors (unless it was told to do so, i.e. through "redistribute
static").

	oli