modem disconnects; leaves message in syslog.log

[Fred Martin_1]

Got a dial-in modem here, which was working on a D390 running HP-UX 11.0.

Moved it over to an RP5450 running 11.11, set it up the same. It worked for a few days, but now whenever you dial into it, it disconnects almost right away.

The syslog is showing the following, entries going in every 30 seconds or so:

getty: cannot vhangup line "ttyd2a2". errno: 2

I have another modem on the same mux, which is used for dialing out, it's working fine.

Have tried power cycling the modem.

Where should I be looking for the root cause?

[A. Clay Stephenson · Accepted solution]

The first thing that I would look for are other references, especially in /etc/inittab, that refer to the same physical port (/dev/tty2a2,/dev/cul2a2,/dev/cua2a2) but with different characteristics. You may have competing processes accessing the same port.

Next, take a careful look at your gettydefs file. Also make sure that a blank line separates each entry.

Don't overlook cabling as well. If you leave a line floating, it could easily leave one of the status bits in an undefined state especially if the pin is actually connected on the host end but left disconnected on the modem end --- it could pick up just enough stray noise to drive you and the port crazy.
You should really use a cable which provides full modem control.

[Fred Martin_1]

Good call: I did a simple ps -ef and grep'd for ttyd, and right away noticed two modems configured for the same device; one outgoing only, one incoming only. There was a daemon running for 3rd-party fax software on the one, and a getty process waiting for a login on the other.

Thanks,
Fred