POE device flapping on switch access port

[Paul Saddy]

I have a switch at a remote office.  I have a Cisco 2851 Router and two cisco 3650 POE switches.  I also have three Aruba 105 POE APs. Two are plugged into one switch, and one into another. Yesterday we had a power issue that caused all of the equipment to reboot.  Everything came back up fine except the two Aruba APs that are plugged into a single switch.  The other AP came up fine.  When I do a show power inline, the two APs show that they are getting power from the switch.

Interface Admin  Oper       Power   Device              Class Max
--------- ------ ---------- ------- ------------------- ----- ----
Fa0/1     auto   on         15.4    Ieee PD             3     15.4
Fa0/2     auto   on         15.4    Ieee PD             3     15.4
 

When I do a show log, it keeps showing the two interfaces going up and down every couple seconds.

006983: *Mar  1 16:33:39: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
006984: *Mar  1 16:33:59: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
006985: *Mar  1 16:34:00: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to down
006986: *Mar  1 16:34:02: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
006987: *Mar  1 16:34:05: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
006988: *Mar  1 16:34:43: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/2, changed state to down
006989: *Mar  1 16:34:44: %LINK-3-UPDOWN: Interface FastEthernet0/2, changed state to down
006990: *Mar  1 16:34:59: %LINK-3-UPDOWN: Interface FastEthernet0/2, changed state to up
 

When I do a show mac-address-table, I can only see the two missing APs for the brief moments that the interface is up.

What I'm trying to find out, is can this still be a part of the running configuration that never got saved or did the power disruption just cause a  hardware/cabling problem?

[Leo Laohoo · Accepted solution]

Too bad your 3560 (FastEthernet model) does NOT support TDR.

Can you re-patch the APs to a switch with GigabitEthernet copper ports?  Doesn't matter if the ports are not PoE.  What matters is for you to run a TDR on the entire length of the cable to eliminate Layer 1 issue.

[Paul Saddy]

Unfortunately that's not an option here unless I ship mine out and walk a standard non-technical user through the process.  But I will tell you that we moved the AP that was in port one into several other ports on the same switch with no response from the lights, show power inline command, didn't show in the MAC-address-table and then it finally worked on port 31. We moved the AP that was in FA 0/2 into several other ports as well as replaced the cable between the switch and patch panel and the only thing I show is that it registers under the show power inline command, but no light on the port and nothing in the mac-address-table. The AP is located in the ceiling so replacing it will be a last resort.

Basically I'm wondering if the device is showing power but not mac in the address table, does that demonstrate that the layer 1 is working correctly?