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2960 router question

cissstc13
Level 1
Level 1

We run into problems where a pc will not connect to the network and when we contact our Telecom group they always want the port info but most of the times the PC is in a different location.

Can anyone tell me if there is a way to look at port history on the 2960 series router?  It seems odd to me that there is no way to determine what IP addresses were connected to a specefic port (even when the PC is off I would think it would still have some type of history).   Most of the time we go to the site and tell the telecom guys which port it's on and I think they reset the port to fix the problem.   I am trying to avoid wasting a trip to a location just to trace a port down.

I am not a networking guy so if I left out any important information let me know.

thanks

2 Replies 2

darren.g
Level 5
Level 5

cissstc13 wrote:

We run into problems where a pc will not connect to the network and when we contact our Telecom group they always want the port info but most of the times the PC is in a different location.

Can anyone tell me if there is a way to look at port history on the 2960 series router?  It seems odd to me that there is no way to determine what IP addresses were connected to a specefic port (even when the PC is off I would think it would still have some type of history).   Most of the time we go to the site and tell the telecom guys which port it's on and I think they reset the port to fix the problem.   I am trying to avoid wasting a trip to a location just to trace a port down.

I am not a networking guy so if I left out any important information let me know.

thanks

In short, no.

The functionality you are looking for is the ARP table - which holds a relationship between IP address and MAC address - and the MAC address table - which tells the switch which port a given MAC address is connected to.

Both of these only apply when the port is active, and have short aging timers. If the device is removed or has its IP address changed, thent here is no "history" of that device - the tables only hold current, active information, of inactive information waiting for timers to expire and be deleted from the table.

If the device is connected and active, it's relatively easy - but your networking guys should be ale to do that for themselves if they have access to the switch.

Basically, you've got no option but to trace the cabling, or find the port number and check records if the device isn't working, or is in a different location from where the problem was.

Cheers.

Ganesh Hariharan
VIP Alumni
VIP Alumni

cissstc13 wrote:

We run into problems where a pc will not connect to the network and when we contact our Telecom group they always want the port info but most of the times the PC is in a different location.

Can anyone tell me if there is a way to look at port history on the 2960 series router?  It seems odd to me that there is no way to determine what IP addresses were connected to a specefic port (even when the PC is off I would think it would still have some type of history).   Most of the time we go to the site and tell the telecom guys which port it's on and I think they reset the port to fix the problem.   I am trying to avoid wasting a trip to a location just to trace a port down.

I am not a networking guy so if I left out any important information let me know.

thanks

Hello ,

If you are asking what ip address were binded with port in recent times ..that cannot be done as you can only see the recent ip to mac binding in arp table by issuing a command show ip arp

Router# show ip arp

Protocol  Address          Age(min)  Hardware Addr  Type   Interface

Internet  171.69.233.22          9          0000.0c59.f892 ARPA   Ethernet0/0

Internet  171.69.233.21          8          0000.0c07.ac00 ARPA   Ethernet0/0

Internet  171.69.233.19          -          0000.0c63.1300 ARPA   Ethernet0/0


Hope to Help !!

Ganesh

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