why do we need extended system id

[sarahr202]

Hi everybody

I understand what is extended system id is but i am at loss as to why we need it. I tried to find some material on Google but could not get a straight answer as to why we need it.

thanks

[Reza Sharifi · Accepted solution]

Hi Sarah,

Extended system id is used to make every bridge id unique

Have a look at the config guide for details:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/spantree.html#wp1037363

HTH

[sarahr202]

Thanks. Reza

Do all cisco switches either have 64 mac or 1024 mac not in between ?