OSPF metric-type

moses12315 · ‎12-06-2007

What's the meaning when a route in OSPF routing table is a type-1 or type-2 .

Thanks

moses

Jon Marshall · ‎12-06-2007

Hi Moses

Both are to external destinations outside the OSPF autonomous system. When a route is redistributed into an OSPF AS it needs a metric.

E1's have a path cost that is the sum of the external cost plus the cost to the ASBR (Autonomous System Border Router) ie. the router that redistributes the route into the OSPF AS.

E2's only have external cost attached to the route ie. they do not include the cost of the path to the ASBR.

HTH

Jon

bvsnarayana03 · ‎12-06-2007

Routes redistributed in to ospf are advertised within the ospf domain by ASBR. These routes are marked as E1 or E2.

In the redistribution command if no cost or metric-type are mentioned, then default cost is 20 & metric-typr is E2. However for E1, you have to specifically mention it in redistribution command.

E1: Cost of path for E1 routes is a sum of cost to reach the ASBR + the cost with which routes were redistributed.

E2 : doesnt calculate cost to ABR, they only have a cost with which these toutes were redistributed.

hope that clarifies.

pls rate all helpful posts.

sorry Jon, i started replying & went on con-call. After the call i finished & posted but u've already replied the same.