Switchport Monitoring

Answered Question
Aug 25th, 2009
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All,


Is there a way to see the last time a switchport was active/connected? I have a 48 port switch with all ports connected to the patch panel but only about 20 ports are active. I would like to see when the last time a port was active so I know if it is safe to use the port for another purpose. Not sure if there are any logs to view to see this. Thanks for any help.


Ken

Correct Answer by John Blakley about 7 years 9 months ago

There are a couple of ways that I know of:


sh int g0/1 summary


sh int g0/1 | inc 5 minute|Last input


The last one will show you when the last frame was received on the port:


Last input never, output 00:00:01, output hang never

5 minute input rate 615000 bits/sec, 53 packets/sec

5 minute output rate 79000 bits/sec, 94 packets/sec


HTH,

John



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Correct Answer
John Blakley Tue, 08/25/2009 - 09:19
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There are a couple of ways that I know of:


sh int g0/1 summary


sh int g0/1 | inc 5 minute|Last input


The last one will show you when the last frame was received on the port:


Last input never, output 00:00:01, output hang never

5 minute input rate 615000 bits/sec, 53 packets/sec

5 minute output rate 79000 bits/sec, 94 packets/sec


HTH,

John



tohoken Tue, 08/25/2009 - 09:24
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Thanks John. This is what I needed. Do you know if you can view a range of interfaces this way?

John Blakley Tue, 08/25/2009 - 09:28
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Hmm, only way that I know how would be to show all interfaces and then filter the same results but include interface names like:


sh int | inc 5 minute|Last input|line protocol


That should show you all interfaces, but as far as using a range, I don't think it can be done with a show command like "show int range etc."


HTH,

John

jms112080 Tue, 08/25/2009 - 09:37
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Is there a MIB to easily pull this info via SNMP?

iyde Sat, 09/05/2009 - 08:10
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Be aware, though, that in some switches a bug (in hardware, as far as I know)makes this unuable, because the show command always says last input never, even though you can see a lot of data passing through.

So in other words, it's unfortunately not always a help for you do do like that.

Another safer way to do it is to clear the counters and then look again at a later time to see if they have incremented or still are at zero.

HTH

Leo Laohoo Sun, 09/06/2009 - 14:47
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If you have a 4500-based chassis or 4900 switch, you can use the sh interface link:


Gi1/13 13 weeks, 23 hours, 41 minutes 42 secs 23:03:52 Sat Jun 6 2009


Hope this helps.

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