AP121 copper link down after reboot.

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Strange problem. I have 18 AP121s on my network. Today I rebooted all of them. All but 5 came back up. The five that are not coming up are all connected to the same Cisco 3750. They are connected to POE ports. The APs light, but what we are seeing is that the link comes up, sits for about 2 minutes, then the link goes down. The switch itself shows there is no link, but POE active. Any ideas?
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Bill Lohrer

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Posted 4 years ago

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Andrew MacTaggart, Champ

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look at the 3750 logs, see if there are any logs related to the ports.

I assume the port is not err-disabled

you could start at Layer 1 and try a different UTP cable or a different switch port or a different switch altogether.

Are there other APs working in the same switch?

Console into AP and run some show interface commands

show int mgt0

show tech
look for logs related to the interface

what color is the AP LED

make sure configuration is as expected.

so if you are trunking on the 3750
that the mgt0 interface is enabled, has the correct mgt vlan and native vlan settings.
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Bill Lohrer

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There are seven APs on this 3750. One is up.

They were up for 4 months, this only occured after a reboot yesterday.

No changes occured

The ports on the 3750 are showing Status - NotConnect.

We have tried other cables/other ports .. N/G

BUT

We have taken an AP from a different building, plugged into one of the down ports. And it works

We have moved one of the bad APs to another building... and it comes up just fine.
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Andrew MacTaggart, Champ

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Maybe take the bad APs to another switch and do a complete upload and reboot of you config.

Have you consoled in to verify the settings in the AP are as you expect?

Cheers
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Jason Zhou

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Hi, Bill, Did your AP121 connected to AC adaptor, or they just powered by the Cisco switch?