CCDP 300-320 - Advantages of route summarization to a client?

vanfaren1978vanfaren1978 Posts: 3Registered Users ■□□□□□□□□□
Hi all.

Someone can help me, I'm not sure what the answer to this question is.

Which two elements comprise the backbone are while designing a new network utilizing IS-IS as the interior gateway protocol (choose two)

A. contiguos chain of Level 2 capable routers
B. contiguos chain of Level1/Level 2 capable Routers
C. set of Level 2 configured interfaces
D. contiguous Level 1 capable Routers
E. set of Level 1 configured interfaces



  • ande0255ande0255 Posts: 1,178Banned
    IS-IS is not on the ROUTE exam, is that a question you saw on the actual ARCH exam?

    I am not really sure, but I would answer B and D for this question, not knowing anything about IS-IS.
    Back in my day we used to route packets on 56k lines, through the snow, uphill both ways.
  • matt333matt333 Posts: 231Member
    A and B I'd say. Level 2 is considered the backbone for IS-IS Level1/2 are borders of the backbone.

    IS-IS is on the Arch exam, theres is a LARGE chapter on it. I am currently studying for this exam as well

    Hope this helps.
  • d4nz1gd4nz1g Posts: 464Member
    id go a and c.

    i think this question would really be " Which two elements comprise the backbone areA while designing a new network utilizing IS-IS as the interior gateway protocol (choose two) ". Isnt that correct? that are in there does not make sense

    so a and c would best describe a backbone (l2) area in isis. you won't necessarily need a l1 area in an isis network
  • Seether12603Seether12603 Posts: 6Member ■□□□□□□□□□
    Answer is A and B.

    To compare to OSPF:

    L2 only routers are your backbone.
    L1/2 routers are similar to your ABRs in that they learn the routes for both the L1 and the L2 Domains.
    L1 only are your intra Area routers. They only learn for their local domain and where the nearest L1/L2 router is for when they need to exit said domain.
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