[181241] in North American Network Operators' Group
RE: Ghosts in our 6 New Ubiquity Pros - provision issues.
daemon@ATHENA.MIT.EDU (Naslund, Steve)
Fri Jun 19 10:11:48 2015
X-Original-To: nanog@nanog.org
From: "Naslund, Steve" <SNaslund@medline.com>
To: Mel Beckman <mel@beckman.org>, Hal Ponton <hal@buzcom.net>
Date: Fri, 19 Jun 2015 14:06:31 +0000
In-Reply-To: <3A3B0EA5-81A2-48B9-A34A-021CEFAE128B@beckman.org>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
That's possible but I if they are re-provisioning on a regular schedule I k=
ind of doubt it. It would be easy to test though. Plug an AP directly int=
o your switch with a quality pre-manufactured patch cord and see how it act=
s. If it exhibits the same symptom it is probably not cabling. Also, have=
you checked your interface counters for any packet errors? Don't forget t=
o look at your controller because if the controller became unreachable for =
any length of time that could easily cause your APs to re-provision as they=
reconnect with the controller. I might set up a ping every second from th=
e site of the access points to the controller and make sure the availabilit=
y of the controller is 100%. If you are on Cisco switches you should have =
log messages regarding PoE be granted on particular ports as well as up dow=
n messages on the interfaces. Do you see the ports going up and down? It =
is important to have NTP on the APs and switches so that you can correlate =
events in time (i.e. did the AP reboot causing the Ethernet link to drop or=
did the link drop causing the reboot?)
Steven Naslund
Chicago IL
>Bob, I've deployed tons of Ubiquiti gear, and have seen this problem befo=
re. It always turns out to be poor quality cable installation. POE does not=
tolerate low quality connectors, especially in outdoor environments. There=
are >many aspects to a quality cabling job, so the best thing you can do i=
s seek out a qualified installer with outdoor POE experience.=20
>
>The most common problem I see is people using crimp-on RJ45 connectors dir=
ectly on the ends of their cable runs. This is not how structured cabling i=
s designed to work, in particular because most crimp-on connectors are inte=
nded for >stranded copper wire (such as that used in very flexible patch co=
rds, designed to run horizontally over only a few dozens of feet), whereas =
the "riser" and "plenum" cable used for long-distance runs has solid core w=
ires. The tiny >teeth in standard crimp connectors are designed to penetrat=
e stranded wire, to make a solid electrical contact. With solid core wire, =
they just bend to the side of the copper core, making tenuous contact, whic=
h will conduct POE >current poorly (resulting in the resets you see) and ev=
entually fail altogether as the improper connection corrodes over time.=20
>
>The correct installation process is to use "punch-down" RJ45 jacks at each=
end of the cable run, and connect from those jacks to your equipment (radi=
o at one end, POE switch at the other). On the outdoor side, the jack/plug =
junction >needs to be in a NEMA weatherproof enclosure, with weathertight f=
ittings. And, for human and equipment safety, you must use shielded Cat5e/6=
cable anytime you go outdoors, grounding only one end (usually the radio e=
nd), and >protecting the cable with an inline lightning protector between t=
he RJ45 jack and the radio.=20
>If you haven't done that, then that's the first thing to fix.=20
>BTW, avoid homemade patch cables whenever possible. Quality factory cables=
are hydraulically pressed and the plug is hermetically fused for a vastly =
superior connection compared to anything you can do with simple hand crimpe=
rs. And >all outdoor cables must be UV-grade cabling with weatherproof shea=
thing and water repellant inside (so-called "flooded" cable).
> -mel beckman
