Flopping Ports

[iggy05]

I having 3 ports that are showing an up and down status in the log. It has been doing it for about 2 months now. The only thing in common is they are Rocket M2 APs near the top of the 300 foot tower. This tower also has a few other whips for the county radio band, a FM repeater, hospital paging system, and a Ham radio system on it. We also have a number of wireless backhauls and a set of 3 M5 APs a few feet bellow the M2 units.

I have seen a number of posts on various forums about how FM and Ham sites can mess with cable frequency and such. Could this possibility be an issue in my case? The only thing that throws me off is the M5 APs are just fine. There are whips above attached at the very top of the tower and maybe it is one of those that are causing the majority of the issue.

This is part of what I am seeing in the log. ports 5, 6 and 7 are M2 devices and does not show up on any of the other devices on the tower. It doesn't last long and it doesn't happen every day. Any thoughts are appreciated.


Apr 23 12:56:57 kernel: link state changed to 'down' on port 6
Apr 23 12:56:58 kernel: link state changed to 'down' on port 5
Apr 23 12:56:59 kernel: link state changed to 'up' on port 6
Apr 23 12:56:59 kernel: link state changed to 'up' on port 5
Apr 23 12:57:00 kernel: link state changed to 'down' on port 6
Apr 23 12:57:00 kernel: link state changed to 'down' on port 5
Apr 23 12:57:01 kernel: link state changed to 'up' on port 6
Apr 23 12:57:02 kernel: link state changed to 'up' on port 5
Apr 23 12:57:48 kernel: link state changed to 'down' on port 6
Apr 23 12:57:49 kernel: link state changed to 'down' on port 5
Apr 23 12:57:50 kernel: link state changed to 'up' on port 6
Apr 23 12:57:50 kernel: link state changed to 'up' on port 5
Apr 23 12:57:51 kernel: link state changed to 'down' on port 6
Apr 23 12:57:51 kernel: link state changed to 'down' on port 5
Apr 23 12:57:52 kernel: link state changed to 'up' on port 6
Apr 23 12:57:53 kernel: link state changed to 'up' on port 5
Apr 23 12:58:04 kernel: link state changed to 'down' on port 5
Apr 23 12:58:04 kernel: link state changed to 'down' on port 6
Apr 23 12:58:04 kernel: link state changed to 'down' on port 7
Apr 23 12:58:05 kernel: link state changed to 'up' on port 7
Apr 23 12:58:05 kernel: link state changed to 'up' on port 5
Apr 23 12:58:05 kernel: link state changed to 'up' on port 6
Apr 23 12:58:06 kernel: link state changed to 'down' on port 5
Apr 23 12:58:06 kernel: link state changed to 'down' on port 6
Apr 23 12:58:08 kernel: link state changed to 'up' on port 6
Apr 23 12:58:08 kernel: link state changed to 'up' on port 5
Apr 23 21:01:40 kernel: link state changed to 'down' on port 5
Apr 23 21:01:41 kernel: link state changed to 'up' on port 5
Apr 23 21:01:42 kernel: link state changed to 'down' on port 5
Apr 23 21:01:43 kernel: link state changed to 'up' on port 5
Apr 23 21:01:44 kernel: link state changed to 'down' on port 5
Apr 23 21:01:46 kernel: link state changed to 'up' on port 5
Apr 23 21:01:47 kernel: link state changed to 'down' on port 5
Apr 23 21:01:48 kernel: link state changed to 'up' on port 5
Apr 23 23:30:25 kernel: link state changed to 'down' on port 5
Apr 23 23:30:27 kernel: link state changed to 'up' on port 5
Apr 23 23:31:16 kernel: link state changed to 'down' on port 5
Apr 23 23:31:16 kernel: link state changed to 'down' on port 7
Apr 23 23:31:18 kernel: link state changed to 'up' on port 7
Apr 23 23:31:18 kernel: link state changed to 'up' on port 5
Apr 23 23:31:19 kernel: link state changed to 'down' on port 5
Apr 23 23:31:20 kernel: link state changed to 'up' on port 5
Apr 23 23:31:36 kernel: link state changed to 'down' on port 5
Apr 23 23:31:37 kernel: link state changed to 'up' on port 5
Apr 23 23:31:38 kernel: link state changed to 'down' on port 5
Apr 23 23:31:40 kernel: link state changed to 'up' on port 5
Apr 23 23:31:41 kernel: link state changed to 'down' on port 5
Apr 23 23:31:42 kernel: link state changed to 'up' on port 5
Apr 24 14:34:14 kernel: link state changed to 'down' on port 6
Apr 24 14:34:16 kernel: link state changed to 'up' on port 6
Apr 24 14:34:21 kernel: link state changed to 'down' on port 6
Apr 24 14:34:22 kernel: link state changed to 'up' on port 6
Apr 24 14:34:23 kernel: link state changed to 'down' on port 6
Apr 24 14:34:25 kernel: link state changed to 'up' on port 6
Apr 24 14:34:34 kernel: link state changed to 'down' on port 6
Apr 24 14:34:35 kernel: link state changed to 'up' on port 6
Apr 24 14:34:36 kernel: link state changed to 'down' on port 6
Apr 24 14:34:38 kernel: link state changed to 'up' on port 6

[sirhc]

Well if your on an FM tower which interferes with normal Ethernet communications that would be my guess.

This is not a problem with the switch but rather the same FM interference that has haunted Ethernet since forever.

You can try running better shielded cable or putting the Ethernet cable in conduit.

Check the up time in the radio and if the radio is not rebooting then Ethernet communications is dropping and not POE so that tells you the Ethernet communications is dropping.

Other possible causes:
Bad port in switch test by switching ports in switch

Bad Ethernet port in Radio test by swapping out radio

Static Charge on Antenna/Radio as there is not an intended ground path of less resistance and when the static charge builds up and snaps down the Ethernet line you lose connectivity. Do you have a grounding system with dedicated ground paths and is the tower ground bonded to the service ground?

[lligetfa]

I having 3 ports that are showing an up and down status in the log. It has been doing it for about 2 months now. The only thing in common is they are Rocket M2 APs near the top of the 300 foot tower.

Rockets are very demanding of power and exceed the published spec of watts drawn. Any deviation from ideal and they become problematic. Since the current is divided across 4 wires (2 Pair), if one of them has a poor connection, the voltage drop can double.

You could try putting a WS-6-MINI topside to shorten up those runs.

[sirhc]

That is a good point Les, but are they rebooting or just losing Ethernet connection? He needs to look at M2 up time and see if they are rebooting or just dropping connection.

Plus 100 meters is near the limit of Ethernet cable and if the cable is not so good and the FM noise could all be contributing.

If he finds they are rebooting I would say Les is correct though and it is a power issue.

But Les is also correct that you could put a WS-6-MINI midway up and that solves your power issue and may help with FM interference?

[iggy05]

Thanks for the info Les and Chris. I have thought about putting a switch up there so that will probably will be the end goal. I try to do some other troubleshooting such as moving the cables to see if that helps first though. I checked up time and it shows 119 days on the radio so they are not fully rebooting. The drop is so fast the only thing noticing the drop is the switch itself.

[iggy05]

One other thing I wanted to add is I did read through your post on grounding a few months back. We don't have grounding like you suggest as of now on this tower or any tower but plan on making it happen in the near future. This is our main tower and consider it very important to try to protect our equipment the best we can. Thanks.

[ict-plus]

We have the same Problem with Flopping Ports on the ws-6-mini and Ubiquiti Nanostation Loco M5 in 3 different Installations...


Jul 14 00:54:00 Port: link state changed to 'down' on port 4
Jul 14 00:54:01 Port: link state changed to 'up' (100M-F) on port 4
Jul 14 01:06:55 Port: link state changed to 'down' on port 4
Jul 14 01:06:56 Port: link state changed to 'up' (100M-F) on port 4
Jul 14 05:21:06 Port: link state changed to 'down' on port 4
Jul 14 05:21:07 Port: link state changed to 'up' (100M-F) on port 4
Jul 14 07:06:31 Port: link state changed to 'down' on port 4
Jul 14 07:06:33 Port: link state changed to 'up' (100M-F) on port 4
Jul 14 11:45:10 Port: link state changed to 'down' on port 4
Jul 14 11:45:12 Port: link state changed to 'up' (100M-F) on port 4

The Ports are going Down an UP for a few seconds. There is no Reboot of the Device, just the Link State is Changing!
On Port 3 of the same Device is a Nanobeam M5-19 without Problems.
The lenght of the cable is about 10m, the Cablecheck ends without Problems.

Firmware:
Netonix ws-6-mini: 1.4.2
Loco M5: 5.6.6

Thanks for any Ideas

[sirhc]

Same suspects as usual to check by swapping things around:
1) Replace radio to check for bad port in radio
2) Swap cable port in switch to test switch port


If still no luck then your down to the usal suspects again:
1) Cable ends
2) Cable
3) Interference with Ethernet communication - try better shield cable