some questions on isis

case i)

here is my topology,

 

r1------>r2-------->r3

 

 

r1 and r2 are in area 49.0001.

r3 is in area 50.0001.

 

 

r3 is having 6 loopbacks

 

2.2.0.1

2.2.1.1

2.2.2.1

2.2.3.1

2.2.4.1

2.2.5.1

2.2.2.1

 

r3 advertises all 6 networks in isis

 

now when i try to generate level 1 summary of 

summary address 2.2.0.0 255.255.248.0 level-1" on r2 

 

it is nor getting advertised to r1.

what is the issue ?.

 

case ii)

 

r1----r2

 

both routers are in same area.(say for ex 49.0001)

 

i configured "is-type level-1" in global routing process on both routers .

i am still  seeing a l1 neighborship.

 

again i configured isis circuit-type level-2 on both the router interface

now i couldn't see any neighborship.

 

i tought interface commands have more priority than the global routing process.

and iexpected a intra area  level 2 adjacency to be formed between routers.

but it didnt happened.

 

 

 

 

Comments

  • Unlike other features where you can override a global setting at the interface level, this is NOT the case with is-type.

     

    If you set is-type level-1 it applies to ALL interfaces. You cannot override this at the interface with circuit-type.

     

    In your case it sounds like you need R2 to be a level-1-2 router so you can't use the global is-type level-1 command.

  • Thanks for the clarification bobby1..

     

    can some one tell me about the summarization issue ?

  • I figured out the answer,Actually there are 2 ways.

    i)redistribute level-2 routes in to level-1 and then summarize it.

    ii)create multiple instance on r2 with level-1 adjacencies between r2-r1 and r2-r3 and then summarize the routes from r2-r1.

     

     

     

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