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Forum Replies

  1. Hi Rene,
    Very Good Stuff.A quick questions for you …
    How R2 know R1 only 2 byte supported before sending any open message ??


  2. Hi Rene,
    I have question in 2-Byte & 4-Byte AS compatibility situation.

    In case of we adding R3 (AS3) and connect it to R2. R1 advertises one prefix (for example: to R2 and R2 will forward to R3.
    What will be in the AS path on R3? (22222222 1 or 23456 1)?


  3. Hello Minh

    This is an excellent question. Essentially what you are asking (allow me to put it more generally) is how is the AS path displayed when there is a 2-byte AS compatible router in the mix?

    Well, if you display the AS path on the 2-byte AS compatible router, then you will see the 23456 AS in place of the incompatible 4-byte AS number. So essentially the AS_TRANS attribute replaces the 4-byte AS number. However, the AS4 PATH number is an attribute that is received by the 2-byte AS compatible device, and is transitive. It may not understand it, but it

    ... Continue reading in our forum

  4. Thanks Laz for the explanation.

    Enjoy your weekend,

  5. Hello Staut

    Yes, that is correct. This is a limitation of the feature and thus must be used carefully,. This could result in routers using the 4-byte AS not being able to reconstruct the entire AS path information correctly.

    I hope this has been helpful!


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