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New Member

OSPF route selection

Hi,

If I have ospf E1 and E2 routes for the same destination with E2 route having lower cost(metric) which one router will prefer to route the packet.

Regards,

Rajesh

2 REPLIES
New Member

Re: OSPF route selection

According to

http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094e9e.shtml#t33

"A type 1 route is always preferred over a type 2 route for the same destination."

//Mikhail Galiulin

Re: OSPF route selection

Hello,

in addition to Mikhail's post, have a look at this Q&A:

Q. How can I give preference to OSPF interarea routes over intra-area routes?

A. According to section 11 of RFC 2328 , the order of preference for OSPF routes is:

intra-area routes, O

interarea routes, O IA

external routes type 1, O E1

external routes type 2, O E2

This rule of preference cannot be changed. However, it applies only within a single OSPF process. If a router is running more than one OSPF process, route comparison occurs. With route comparison, the metrics and administrative distances (if they have been changed) of the OSPF processes are compared. Route types are disregarded when routes supplied by two different OSPF processes are compared.

Regards,

GNT

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