[WISPA] Motorola PTP radios killing switch ports
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. 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
Re: [WISPA] Motorola PTP radios killing switch ports
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? If it does you might look at http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00806cd87b.shtml 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 ___ Wireless mailing list Wireless@wispa.org http://lists.wispa.org/mailman/listinfo/wireless
Re: [WISPA] Motorola PTP radios killing switch ports
I am tempted to say, most likely a grounding or a ground loop related issue. Most Enterprise class switches don't have any kind of surge protection built-in on the switch. Some of the POE switches do however folks like Mikrotik or even most of the industrial switches have such protection built in. Have you tried connecting in indoor Ethernet surge protector right before the switch port ? Regards. Faisal Imtiaz Snappy Internet Telecom 7266 SW 48 Street Miami, FL 33155 Tel: 305 663 5518 x 232 Help-desk: (305)663-5518 Option 2 or Email: supp...@snappytelecom.net - Original Message - From: Fred Goldstein fgoldst...@ionary.com To: wireless@wispa.org Sent: Monday, February 3, 2014 5:36:02 PM Subject: [WISPA] Motorola PTP radios killing switch ports 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. 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 ___ Wireless mailing list Wireless@wispa.org http://lists.wispa.org/mailman/listinfo/wireless
Re: [WISPA] Motorola PTP radios killing switch ports
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
