BGP question

[sarah12345]

Cisco has a proprietary BGP attribute called weight. Why do we need it? It seems to me it does similar things, but has less capability, than local preference?

[Harold Ritter · Accepted solution]

Weight is not a BGP attribute as it is not included in BGP update messages. It has only local significancy and has precedence over the local-preference.

Please refer to the following document for more information on the BGP Best Path Selection Process.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094431.shtml

Hope this helps,

[Harold Ritter · Accepted solution]

I forgot to answer the "why do we need it" part of your question.

It is mainly used to override any attributes that might be received from any other peers, especially in the case of locally originated prefixes (via redistribution or network statement).

Hope this helps,

[sarah12345]

That answers my question. Thanks a lot!

Cheers,

Sarah