I recently deployed several ANT-2x2-5314 antennas to several MSR-4000's so that we could make use of DFS channels for some backhaul links to eliminate channel reuse/interference.
The deployment is at a research factility in a remote area in Colorado. The nearest town is about 4 miles away. Since making use of the DFS channels, we are seeing some connections drop and not reconnect for 20-30 mintues. The radios that should be connected will be able to see each other, but they will be unlinked due to 'peer gateway cost higher'. There's no other radio for the far-end to connect to, there's no blacklists, the near radio will not be at it's peer limit, the RSSI should meet the minimum required, etc. There's no reason that I can see for the radios to not make a connection.
When this occurs, the following message is noted in the logs:
Jun 20 01:50:49 MSR4000 PoE: Interface:Warning:core2:Mon Jun 20 01:50:49 2016 :Radio interface wifi1 Channel has changed to wireless mode 802.11na channel 116
Nobody is changing the mode of the interfaces as the configuration has been set for many weeks now, so the radio should already be in that mode. I believe the connection fails at the time this is logged and it will be some time after this message before the radio will reconnect.
The radio can run for weeks without issue, then we will get this several times throughout the day. So far we have seen this on all of our DFS links on various channels (100, 108, 116, 136), but we've never seen this on a non-DFS channel.
When I check the channels on the radios having this issue, the radar counters will be zero. The signal quality for these links are typicaly in the 80-83% range.
Any suggestions on other things to check would be great. We checked with our partner and they had never heard of this warning before.