Switch port Up but cannot see MAC

Unanswered Question
Jun 16th, 2009

The switchport is connected to a patch panel which in trun is connecting to a terminal. I can see the switchport UP but cannot see the MAC address. Any thoughts please help.

I have this problem too.
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Leo Laohoo Tue, 06/16/2009 - 14:04

In my experience, the following reasons may apply:

1. The host is powered up to a power source (thus the NIC is UP), but the host may have been turned off; or

2. Host may have a dual NIC.

Hope this helps.

glen.grant Tue, 06/16/2009 - 15:03

try pinging the device . The switch learns macs when it see's traffic from the device . The mac table ages out after 5 minutes I believe if it sees no traffic.

pompeychimes Tue, 06/16/2009 - 20:13

Confirm that both ends see the link as up

Gen some traffic (Ping the device)

Hard code speed and duplex settings

Verfiy cabling and patch panels

Try another device

Try another port

prakadeesh Thu, 06/18/2009 - 00:45

Thanks all for the comments,

I am also suspecting something with the cabling only, I dnt think there is a dual connector, but i think there is a splitter some where in the cabling structure.. i will check the cabling

lance.elmshaeuser Thu, 06/18/2009 - 07:14

I also suspect wiring. We have this frequently on our switches with older cat3 wiring (scary I know). The port will be up but to mac and it usually comes down to a loose punch down or some other basic wiring issue.


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