Cisco 6500 - Oversubscribed Ports

[zaradell]

Good afternoon to you all

I was wondering if you have a notion on what oversubscription ports are and what are they for? A simple explanation if possible.


And if so, what´s the show command to see what ports are Oversubscribed?

 

[ISPKing]

Lol, Oversubscribed ports are ports the are utilized officially above their hard bandwidth limitation. For instance Port 1 is a 100mbit up link port to a core router, somehow your network generates 400mbits of outbound traffic. Now your trying to smush 400mbits through a 100mbit passage, Thus oversubscribed.

Sho int fa0/X
where x is the port number
and look at the bps thought put and multiply by 1mil to get mbits per second.

CCNP

 

[vipergg]

On switches a lot of port hardware is based on asics which control 4-8 ports on a slot . Each of the asics has a certain amount of bandwidth to the backplane of the switch . If a asic has a 4 gig backplane bandwidth but there 8 1 gig ports on that asic then those group of ports are oversubscribed for those given ports . This is only an issue if you get more than 4 of those connections running a full gig and is what cisco bets on when designing their switches this way . They do make equipment that is not oversubscribed also .