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Cisco 1252 AP no link across cable attached to 3750X switch

I am hoping that someone might have experienced this already and might have an answer for me.

I have a site with 12 Cisco AIR-AP1252N-A-K9 AP's that were converted to CAPWAP ( code. The issue is really wierd, some of the AP's won't come on-line on certain cable runs.  They seem to get power but no link light on the switch. We have had the cables tested with no faults found and have put a laptop on the end of the cable and it works fine. The longest run is 200 ft...  All of them work fine when connected directly to the switch; but when put into the ceiling some don't work.  but sometimes when we swap a working one and a non-working then they both work.

anyone have any ideas?

Hall of Fame Super Gold

Re: Cisco 1252 AP no link across cable attached to 3750X switch

I know how good you are so I ain't here to criticize you.

I always "shudder" at phrase "have had the cables tested with no faults" particularly when they're done by the cable contractors themselves.  Some cable contractors here in Australia do short cuts.  For instance when we ask them for test results, they sometimes fudge up the reports (they say it's "pass" but visual inspection shows the cable curled up and leaning against the wall of the cabinet not terminated) or use sub-standard TDR tester (cheap ones test only two pairs).  We always ask to SEE them use Fluke TDR/OTDR.

Since you have 3750X, you can run the TDR yourself.

Just to let you know that using the "test cable tdr interface" command, we were able to catch alot of "shonky" cable works by our contractors and they are not happy.   In most cases, the Cat5E ran >100 metres and in two cases, the Cat5 (not Cat5E) were JOINED to a Cat6.  Nice!

Just now, we are wondering why an 1140 negotiated to 100Mbps instead of 1Gig.  TDR shows that the 3rd pair is short-circuiting.  Love this function!  He he he ...

New Member

Re: Cisco 1252 AP no link across cable attached to 3750X switch

hi leolaohoo ,

wonderful commands , most of access points connectivity related to cable issue most of time one or two pairs was short so if this commands work it will be very useful


Re: Cisco 1252 AP no link across cable attached to 3750X switch


     No offense taken, I believe it's cabling, but they have done media certification several times and it's passed, but other devices work fine on the end of the cable, that's the wierd part, but I'll try the TDR command and see what happens.