On 2/3/2014 6:30 PM, l...@mwtcorp.net wrote: > On Mon, 03 Feb 2014 17:36:02 -0500 > Fred Goldstein <fgoldst...@ionary.com> wrote: >> We've been seeing a strange problem on a network we operate that has >> a lot of (mostly old) Motorola PTP400 radios on it. These use the >> Motorola PIDU POE injector. They're connected to HP Procurve and >> Cisco 3550 switches. >> >> The problem is that some radios literally kill the switch ports. >> Sometimes it begins with alignment and CRC errors on the switch >> ports. But then the port might fail, and the radio has to be plugged >> into another port... until it fails. It's an odd failure mode too; >> the 3550 thinks the port is OK, and sees it as going up and down as >> the PIDU is attached and detached, but it doesn't pass packets. >> >> The "fix" is to insert a small dumb switch to isolate the 3550 from >> the PTP, but that's kind of a nasty hack. Ciscos seem somewhat more >> susceptible than HPs, but we're migrating towards the venerable >> Ciscos because they are more manageable. We think we have the speed >> and duplex matching right. And while we can't be sure, the cabling >> in most cases looks okay. >> > Hi Fred, > > I don't have that radio but I've had port problems from time to time. > > I noted that you said the switch showed the port as up but; > > On the Cisco Switch, if you do a 'show interface status' does the > switch port show status of err-disabled?
Nothing that simple. We're well aware of the errdisable states, and all of our 3550s have been configured to recover automatically from these errors. We've also done the port config shutdown followed by no shutdown, which clears out everything with any port states, including BPDU guard port blocking. Furthermore, nothing else seems to be able to communicate when plugged into one of those ports once killed. We suspect there could be some kind of DC leakage from the PIDU onto the data port, and that the PoE voltage is on the higher side. > >> Anybody else run into this? Thanks. >> >> -- >> Fred R. Goldstein k1io fred "at" interisle.net >> Interisle Consulting Group >> +1 617 795 2701 >> >> _______________________________________________ >> Wireless mailing list >> Wireless@wispa.org >> http://lists.wispa.org/mailman/listinfo/wireless > > Larry Ash > Network Administrator > Mountain West Telephone > 123 W 1st St. > Casper, WY 82601 > Office 307 233-8387 > -- Fred R. Goldstein k1io fred "at" interisle.net Interisle Consulting Group +1 617 795 2701 _______________________________________________ Wireless mailing list Wireless@wispa.org http://lists.wispa.org/mailman/listinfo/wireless
