From: Salau,Olayemi (Olayemi.Salau@southampton.gov.uk)
Date: Fri Jan 05 2007 - 07:30:15 ART
Hello,
EIGRP s1/1 s1/0 OSPF
R1 ----192.168.2.0--------- R2 -----192.168.1.0--------- R3
S1/2|
|
|
192.168.3.0
|
|
|
R4
In this setup, s1/0 is participating in OSPF process, s1/1 in EIGRP, but
s1/2 is just a mere direct connection.
Now Redistribution is like teaching an English how to speak French. So
if I redistribute OSPF into EIGRP (without any route-map) EIGRP will be
able to reach the 192.168.1.0 network right? Yes, but it wouldn't know
how to reach the 192.168.3.0 network.
Now using a route-map option, the default match criteria is any, so if
you use
route-map exe5do permit 35
set metric 10000 10 255 1 1500
literally, you imply:-
route-map exe5do permit 35
match any
set metric 10000 10 255 1 1500
This will be the same thing as doing the ffg without the route-map
option
router eigrp 1
redistribute ospf 1 metric 10000 10 255 1 1500
However, if you use the match route-type internal you are saying, match
only those internal OSPF routes you see from the Routing Table on R2.
Ofcourse R2 will install 192.168.1.0 as directly connected route within
the Routing Table, Why? Administrative Distance ... Directly Connected
Routes have AD of 1 and OSPF have AD of 110, so 192.168.1.0 will not be
seen as OSPF Route. I know this is basic so please forgive me, but it's
good to go down to the basic sometimes to clarify complex things ... at
least, that's what my dad and Michael Faraday taught me.
So match route-type will neglect the 192.168.1.0 network and wouldn't
teach our EIGRP friends how to get to it.
Now if you want to redistribute the other way round, ie. EIGRP into OSPF
... like things are a little different, don't want to bother us with
tautology, but once you use "subnets" option with redistribute under
OSPF process, then our OSPF friends will know how to get to 192.168.2.0
and the networks beyond!
Hope this helps ... just hope I didn't get somethings wrong in my
analogies, but the brain is getting worked up this days ... Regards
Many Thanks
This archive was generated by hypermail 2.1.4 : Thu Feb 08 2007 - 23:46:55 ART