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Issue with 7800N Router getting stuck / storm when new Cisco phone added to network

Posted: Mon Nov 14, 2016 11:11 pm
by marcusjclifford
Hi I have 2 Billion 7800N routers, running Software Version 1.06h.dt2

Whenever I introduce a new Cisco phone onto the network within about 2 hours (variable time - can be minutes or over an hour later) my 7800N becomes unresponsive over the Ethernet interface. Connectivity to the router is lost.

Wireless devices still work fine. The lights on the front of the router look like indicating lots of network activity.

To try to resolve this I ran WireShark and indeed have found the issue:
The switch is producing (many 10s of times a second) the following:

Code: Select all

180	2016-11-14 22:40:28.063430	Spanning-tree-(for-bridges)_01	Spanning-tree-(for-bridges)_01	MAC CTRL	60	Pause: pause_time: 65535 quanta
181	2016-11-14 22:40:28.096977	Spanning-tree-(for-bridges)_01	Spanning-tree-(for-bridges)_01	MAC CTRL	60	Pause: pause_time: 65535 quanta
182	2016-11-14 22:40:28.130495	Spanning-tree-(for-bridges)_01	Spanning-tree-(for-bridges)_01	MAC CTRL	60	Pause: pause_time: 65535 quanta
As per the time stamps this is happening many times a second, this is what is causing the loss of connectivity.

This ONLY happens when a new Cisco phone is introduced to the network. It happens once per phone, and after that does not happen again.
I have had 100+ day up-time on the router without issue, but once a new phone is added I can guarantee this will happen.

Rebooting the router via power off - on is the only way to restore service.

I have replicated this exact behavior on my second Billion 7800N, so it is not a "one off" thing.

Any ideas welcome.
Thanks
Marcus