Ethernet port flapping to 100M on 3000 and 3000L APs

We have two 3000L APs and one 3000 AP deployed on our tower. One of the 3000Ls and the 3000 won't hold a 1G Ethernet connection into our Netonix swtich. We climed the tower and replaced both Ethernet ends. They train up at 1G and then minutes to days later go back to 100M and stay there until we reboot the AP or power cycle the switch port. These same cables were powering 2000 APs with no issues for 2 years. Cable is UBNT carrier grade cable with double shielding and is only ~5' long between the switch and the radio.

Anyone else seeing Ethernet issues with 3000 series APs?


@Au Wireless wrote:

We have two 3000L APs and one 3000 AP deployed on our tower. One of the 3000Ls and the 3000 won't hold a 1G Ethernet connection into our Netonix swtich. We climed the tower and replaced both Ethernet ends. They train up at 1G and then minutes to days later go back to 100M and stay there until we reboot the AP or power cycle the switch port. These same cables were powering 2000 APs with no issues for 2 years. Cable is UBNT carrier grade cable with double shielding and is only ~5' long between the switch and the radio.

Anyone else seeing Ethernet issues with 3000 series APs?


Hi Chad,

Could you please send yo me Tech Support Files form ePMP3000 and ePMP3000L after the issue happened?

fedor.trutsko(at)cambiumnetworks(dot)com

Thank you.

The longest run we have to 3000's is 325' passing through 2 Cambium 1Ghz surge suppressors. We have 3 around this distance, with a 4th around 295'. 3000's on antenna coral at top of a larger water tower with Netonix at bottom. Surge suppressors are also one at top, one at bottom. Everything above is bonded to bus bars, which are bonded to the tower, putting everything at the same ground potentiaI. I just checked the logs of the Netonix. I cleared them on the very early morning of 10/18. I show no port changes since that time on any of the 4 AP's. Have been holding 1Ghz full. There are 3 cell carriers on this tower. We have a PTP550 on the cat walk around 170'. I think we have about 210' of cat5 going to it, also passing through two Cambium 1Ghz suppressors. No issues with it. 

Is your switch bonded to same ground as AP's (Antenna and Radio)? Since everything is so close together on your tower, one single ground point for all AP's and Netonix would be most preferable. The Netonix is sensitive to ground difference potentials, static currents, and ground loops, causing sync and POE issues. Netonix actually states this a few places on their forum. They talk about it some in this post .  You may already be aware of all this, and have it grounded well. Just in case you do not, this may help. 

We are grounded at top and bottom to the same ground. Switch and radios are grounded. This same setup worked great for years with 2000 APs but failed as soon as we put up the 3000 APs. I'm going to climb the tower as soon as the snow lets up and see if wind (90+ MPH last week) messed up any ground wires but I seem to recall the ports flapping before our winds.

"Netonix at bottom. Surge suppressors are also one at top"

Not anything to do with anything here but I didn't think you were supposed to use surge suppressors with Netonix switches, it kills the PoE on the netonix when the surgesupressor, uh, supresses.  Fuses only on Netonix PoE.


@brubble1 wrote:

"Netonix at bottom. Surge suppressors are also one at top"

Not anything to do with anything here but I didn't think you were supposed to use surge suppressors with Netonix switches, it kills the PoE on the netonix when the surgesupressor, uh, supresses.  Fuses only on Netonix PoE.


Not sure where that came from. I have never seen on the forum to not to use suppressors with Netnonix switches. I did see that sirhc (or however it is spelled) does not use them. But... there is a post where he says suppressors are "OK" to use.

Even if Netonix did/does say not to, I will continue to use them. I have done comm work for over 20 years and have seen many times the damage surges and lightning can cause. We ground by the Motorola R56 standard. Luckily for us the cell companies already grounded this site by these specs. For us, the AP radio and Sector antenna are bonded to a ground bus, which is grounded to the antenna corral. This is at each AP/Sector. The Cat5 from each AP runs from corral, down bowl, to the catwalk where we have a panel with Cambium surge suppressors mounted. Surge suppressors all grounded to a bus bar which is grounded to the catwalk railing.

Ethernet cable then goes down the messenger rings/pipe to the bottom of the tower where we have a second panel with surge suppressors mounted and grounded to a bus bar, which is mounted and grounded to the messenger pipe.   On each end of our bus bar mounted to the messenger pipe is 2ga wire going to ground rods which are tied to the halo ground system already installed by the cell guys.  Our equipment cabinet is maybe 10' from the messenger pipe. The bus bar in our equipment cabinet is then grounded to these ground rods as well, making one single point ground at bottom of tower.

Yes, I understand a clamped or shorted surge protector can damage the POE circuit on the Netonix. So will a shorted ethernet port on an AP due to lightning, etc. I would rather replace a few surge suppressors and a Netonix switch than to replace AP's and a Netonix switch because the AP's and switch took the full force of a surge. I can always send the Netonix back for repair. Also, the surge suppressors give 4 places (at AP, SS 1, SS 2, and at the switch housing) to dump induced currents off my ethernet braid (they also give 2 extra places for possible problems, I acknowledge that as well). 

Just my take on things.

same Problem, Port is Flapping after change from epmp1000 to epmp3000l.

We ended up swapping back to the 2000 APs and the port hasn’t flapped once on them. Same Ethernet cable and switch ports.

yes, back to epmp 1000 everything is fine!