Several years on, and this fault is now a rare occurrence, but today I have once again noticed the disappearing 3G dongle. Last thursday at 23:35 BST there was a clueless.aa.net.uk log entry saying "LNS planned switchover". Not surprisingly, the clueless.aa.net.uk CQM graph shows no PPP link after that, but either the PPP connection is not established or somehow CQM graphing isn’t happening for another reason (CQM graph shows purple background). When I noticed the problem today, I commanded the Firebrick to cycle the power supplied to the USB interface in order to reinitialise the 3G NIC, and then all was well.
The LNS thing is perplexing: why should that have anything to do with the 3G NIC getting into a bad state? Something happened on or after Thursday that was genuinely bad, because it required a 3G-NIC-related fix action, although nuking the USB i/f was perhaps overly drastic.
I have played with the f8lure.mouselike.org service in the past. I should be able to get this to ping-monitor the 3G USB NIC and alert me via email when the 3G NIC goes down? Is that correct ? What do I need to check ?
- Have already set up an IPv4 address specifically for the WAN-facing upstream of the 3G USB i/f alone. Indeed, for some reason, I see that I have two such addresses allocated - don’t have a clue why. So one can be returned to AA.
- Check firewalling allows ICMP pings.
- Set up f8lure.mouselike.org; Will need to find the ping email alerts setup destructions page, as I currently can’t see it for the life of me.
- Anything else that I’ve forgotten?
I got stuck with this procedure though, because pinging from an external source address failed; presumably either due to some firewalling somewhere, but I can’t see it, or a routing choice, given that this is a failover interface and only supposed to be active during failover. So will have to check the routing.
Checking routing settings in clueless for that single IPv4 address, all looks correct. So will need to ask AA as I’m stuck.
