04-02-2015 06:03 PM - edited 03-07-2019 11:23 PM
Hi, I'm studying for the CCNA, and am trying to learn and experiment with OSPF in packet tracer. I am having trouble with setting up a ABR to advertise a summary route for area 0 to another router in area 1. Lets say I have:
R1:
router ospf 1
network 192.168.1.0 0.0.0.255 area 0
network 192.168.2.0 0.0.0.255 area 0
network 192.168.3.0 0.0.0.255 area 0
area 0 range 192.168.0.0 255.255.252.0 <-- my summary route
ip route 0.0.0.0 0.0.0.0 10.1.1.1
default-information originate
R2:
router ospf 1
network 10.1.1.0 0.0.0.255
network 10.1.2.0 0.0.0.255
network 10.1.3.0 0.0.0.255
Assuming R1 in area0 is my main network, and I want to advertise my summary route to the area 1 router, what would I have to do?
I hope that makes sense. Thanks!
04-02-2015 07:04 PM
Hi,
Have a look at this document for examples of route summarization.
https://supportforums.cisco.com/document/116011/ospf-inter-area-route-summarization
HTH
04-02-2015 09:02 PM
Well I think I've got it now. I think I was over complicating it, by not realizing that a router could easy advertise routes to multiple areas, eg:
router ospf 1
net 192.168.1.1 area 0
net 192.168.2.1 area 0
net 10.10.10.10 area 1
net 10.10.20.10 area 1
etc, and then using the 'area 0 range 192.168.0.0 255.255.252.0
Also, as I understand it: If you put a default route on an ABR with default-information originate, the route is advertised to both AS's. But if the route is on either of these AS's, you can't do this because a routing loop will occur. Is this correct?
thanks again
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