Folks, I needs some help here, please. We have a Balance 20 (HW3, FW 7.0.2) at a remote communications site which is fed by Time-Warner/Spectrum cable (WAN 1), Sprint 4G (via wi-fi adapter, WAN 2), and AT&T 4G (set as cold standby on WAN 3 - USB). Once in a while WAN 1 fails. (Always at the worst time, of course.) As I write this it shows “connecting” – but never does. So, as I write this, WAN 1 is down – still “connecting.”
Here’s what I’ve done to troubleshoot:
- Connected a laptop directly to the Motorola SB6141 cable modem. A 1GB link was established and connectivity was as expected.
- Rebooted the cable modem (several times) – no effect.
- Rebooted the B20 – no effect.
- Changed the WAN 1 port setting from “Auto” to 1Gb, full duplex, with “advertise speed” checked [going back through the forum this seemed to fix some situations for others] – no effect.
- Changed ethernet cables – no effect.
- Swapped WAN 1 and 2 (changed Spring 4G to WAN 1 and T-W to WAN 2 – Sprint 4G worked fine on the WAN 1 port.
So, where’s what I think I learned:
- All cables are OK.
- I had originally suspected a bad port on the B20 - not true as the other WAN worked fine there.
- The modem is OK as it worked fine with a computer connected directly to it.
- The frequently-recommended “solution” of locking the B20 port to 1 Gb did not resolve the issue.
At this point I’m out of ideas. I’ll appreciate some help.
Added: I just took one more step to troubleshoot: Going back through the forum I found where it was suggested to insert an unmanaged switch between modem and router. I did. Presto! Connectivity!
While this is a great troubleshooting step, and is OK on a temporary basis, we certainly don’t want to leave it that way! (Kludges are not welcome here.) Obvious question: “What changed?” – and the answer is “nothing!”
So, how should this issue be addressed in the longer term?