How do you identify unused switch ports?

[andf1]

Hello all,

We are a campus with about 3000 switch ports. The switches used are either Cisco Catalyst 3548XL, Cisco Catalyst 4506 or Cisco Catalyst 6509s. I have been asked to come up with an easy and automated method of identifying switch ports that have been unused for more than 30 days. Does anyone know how this can be done? Is there an SNMP MIB that could provide me this information?

Any ideas or suggestions are greatly appreciated.

Thanks,

Andy

 

[baddos]

You could log all of the events to a syslog server, and then have your syslog server log to a SQL database. Then you could run a Crystal report on the database every thirty days and see which ports are active.

Kiwi syslog server will do this, and it's pretty cheap.

 

[InDenial]

First of all you need to define : unused.

what is unused to you?.. Does it mean that the interface counters are 0 ( e.g. there is no device attached to it) or that there is a max to the amount of data that went through the port? (there is an unused device attached to the port)

Checking for interface counters is possible using snmp. i am not sure about wich OID you need for it. You might check

http://www.mibdepot.com

Second you have to ask yourself.. Why do you want to know it?

Do you want to know it because you have to do an inventory and to see if the network needs expanding or maybe some switches can be shutdown? Remember that if there is a hub on an interface and 4 devices are attached you have to count 4 ports.

response to baddos:

I do not think it works.

the port is down before day one and on day 30 it is still down. there won;t be any syslog messages from this interface so the port is not marked as unused.

It is only possible if you have next to the syslog database an inventory database from ports that are in the network and if their status was up or down at the beginning of the 30 day cycle. Check based on the port database if there is a syslog message for that interface. If the port was up and there is a syslog message then it is used. If the port was down and there is no syslog message the port is unused. But still. If the port goes up once and goes down again after 10 minutes because the port was used for a test I would mark this port as unused.

So the only way to check is to check the port counters using snmp. And again.. if there only went a small amount of data over the interface during those 30 days.. must hte port being marked as used or unused?



InDenial