[chucken]

Has anyone had a problem where a working unit was unplugged, then later plugged back into the network and the registration process seems to have stopped? This is with a 2100, though I had a similar state with the 3000's once before. The only way I found to get it to stop was to factory reset, then re-enter my config.

The 2100 is passing normal traffic, and it looks like it should be at least trying to register, but an upstream packet trace is showing nothing happening. The status page shows "Not Registered" like the line has been disabled, though it hasn't. Is there some way to kickstart the registration, or some way to diagnose when it seems to be doing nothing?

[PhoneBoy]

Enable debugging in the device, fire up a syslog server on your PC.

[chucken]

I tracked down my issue, and I'll post details in the event that someone else suffers similar troubles.

Where the admin interface allows turning on the web server interface, and setting user and admin passwords, there's a field labeled Restricted Access Domains. I assumed this was a way to further restricted admin access, and entered a comma separated list of address blocks like 192.168.111.1/24, including both the public and private blocks of addresses I use to access the interface. The manual says, "This feature is used when implementing software customization." which doesn't really tell one much about what this does.

Anyway, with this value set as described above on several boxes, everything was working as expected (though I had never tried to see if I could access the admin from a site not in the configured address blocks) but then on one box when I did this it simply stopped registering after a power cycle. It didn't even try. Removed the entry, and it restarted.

In the end, I have no idea what this feature does or why it would impact the registration process - but if you use it thinking it might provide a little extra security or DoS protection, it may not do what you're expecting.