Netonix Forums

Odd case here. We've started getting reports of customers with FEM2Cell units suddenly stop working. These units have of course been up and functioning for years. Even behind Netonix switches.

Recently I've enable 2 changes on the sector facing ports of 2 WS-24-400's

1. Enable DHCP Snooping

2. Changed MTU on netonix port only to 1528


Since then any unit located downstream of these sites has been unable to connect. I've moved the unit to our office which is directly on fiber and no issue presents. Also doesn't present on sites not downstream of the switches.


I've reverted the above change on the ports facing the sectors of the affected customers and set MTU back to 1518 (was the setting prior) with no luch on restoring connection.


Anyone see something similar or have possible insight?.

I would leave the MTU set to 1528 if not higher, no idea what these devices are but they may encapsulate their communications.

Try a higher MTU for grins and giggle.

I would leave DHCP snooping off as it blocks certain ports.

They are cell extenders.

They simply connect and then try to establish a vpn to in this case ATT. The reason I bring it up at all is that it's only affecting sites behind netonix switches and not anything else. very very strange. (The device itself runs at 1492 MTU according to the docs)

for reference.
http://www.att.com/att/microcell/

ircactus wrote:They are cell extenders.

They simply connect and then try to establish a vpn to in this case ATT. The reason I bring it up at all is that it's only affecting sites behind netonix switches and not anything else. very very strange. (The device itself runs at 1492 MTU according to the docs)

for reference.
http://www.att.com/att/microcell/

I would still try a MUCH LARGER MTU for grins and giggles?
I would also make sure DHCP Snooping is disabled on the needed ports (in and out)?
Also do you have IGMP Snooping enabled or Disabled, we had added IGMP Snooping in later versions of the firmware?
Maybe the UDP or CDP that added later affected it somehow so try disabling those features.
Try v1.3.3rc5 maybe?

As the followup. dhcp snooping in this case was the cause. The problem is solved for now but I gotta say I'm interested in finding out why specifically.
The issue only presents itself on att microcells. No other carriers were affected. With 1500 or so clients on net in a rural setting, these devices (from all the carriers) are used extensively.

If you're curious 1.2.2 running on those particular switches. Will upgrade to latest stable on next maint cycle.

Resolved..

DHCP Snooping blocks certain ports that DHCP servers use to advertise/hand out leases so apparently they are using those same ports.