My question is if an OSPF router learns a network from two different paths. One with a higher cost but it is a intra-area route. The other one with a lower cost but it is a inter-area route. It turns out the route choose the first one with a higher cost. Is this how it supposed to be? or it should always choose the one with a lower cost regardless of the route type?
Once OSPF has selected the longest match to the specific destination address which in your case you end up with 2 matches, the Intra area route and the Inter area route, it then uses the path type in the route selection process. In order of preference
3) E1 external
4) E2 external
So yes OSPF will choose the Intra-area route over the Inter-area route.
The OSPF routing process shall compare between any equal costs routes with the same area type, so if you have one Intra-area route to specific destination and another Inter-area route to the same destination, Regardless the cost the router will select the Intrea-area route over the inter one, because it's logic to keep the traffic within the area instead of send it out the area,
Also the below list shown the OSPF routes checklist:
1) Intra-area (To keep the traffic internal)
2) Inter-area (Prefered over External)
3) E1 external (Over E2 because the cost to the ASBR counted)
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.