topic Re: Quirky telnet login over PCI serial mux card in Operating System - HP-UX

Quirky telnet login over PCI serial mux card

Ed Hon — Tue, 12 Mar 2002 19:48:15 GMT

If I telnet over the LAN to the N-Class, everything works fine. If I telnet over a dial-up connection to the PCI serial mux card, it sometimes behaves strangely, when I try to terminate the session. Most of the time, when I type 'exit' at the shell prompt, it will say 'logout root' and terminate the dialup connection. Sometimes, however, it will show the login prompt again, and I cannot break out of the login loop. If I manually break the phone connection, the next time I dialin, the port will be hung up. I have to find another port, login, run kermit against the other port, and issue an AT command to free the port. My /etc/inittab entry is a0:3:respawn:/usr/lbin/uucp/uugetty -t 60 -h ttyd2a8_hw 19200 . It also seems more likely to happen, if I leave the session idle for a longer period of time. I'm using hardware flow control. Any ideas on what's going on?

Re: Quirky telnet login over PCI serial mux card

K.Vijayaragavan. — Wed, 13 Mar 2002 09:11:38 GMT

In the "/etc/inittab" file entry, "a0:3:respawn:/usr/lbin/uucp/uugetty -t 60 -h ttyd2a8_hw 19200" ,
"-t 60" sets timout value to 60 seconds.

If no one is typeing anything in an oppen telnet session within 60 seconds then the connaection will be closed.

If required you can set more timout value say (300secs=5min) or take out the "-t 60" option.

-K.Vijay.

Re: Quirky telnet login over PCI serial mux card

Ron Kinner — Wed, 13 Mar 2002 14:08:08 GMT

Vijay's right but you might want to look at your modem string too. Is it set to use DTR? Is the no carrier timeout set to something besides 0?

Ron

Re: Quirky telnet login over PCI serial mux card

Ed Hon — Thu, 14 Mar 2002 16:49:50 GMT

One thing I need to clarify is that I never loose the connection. I'm always connected, but when I exit the shell to logout, I sometimes get into a logon loop.

Re: Quirky telnet login over PCI serial mux card

Ron Kinner — Fri, 15 Mar 2002 02:21:48 GMT

Still think you need to look at your modem string. The modem should hang up when the connection times out. That fact that it doesn't is probably confusing the system.

Ron

Re: Quirky telnet login over PCI serial mux card

Ed Hon — Fri, 15 Mar 2002 18:34:05 GMT

DTR is set for normal (non-override) operation. I'll try adjusting the timeout parm -t for uugetty. Is there any problem, if I left it out entirely?

Re: Quirky telnet login over PCI serial mux card

Ron Kinner — Fri, 15 Mar 2002 19:42:25 GMT

You can take it out if you like.

What OS are you using?

What do you have for /etc/gettydefs

What kind of modem do you have?

Do you have Chat scripts down in /etc/uucp/Dialers? What do they say?

I'm wondering about the hangup timer:
modem(7)

The last timer defined, the hangup timer, is used for both CCITT and
simple modes. This timer controls the amount of time to wait after
disconnecting a modem line before allowing another open. This time period should be made long enough to guarantee that the connection has
been terminated by the telephone switching equipment. If this period
is not long enough, the telephone connection may not be broken and a
succeeding open may complete with the old connection.

Ron

Re: Quirky telnet login over PCI serial mux card

Ed Hon — Mon, 18 Mar 2002 19:59:02 GMT

Ron, the O/S is HP-UX 11.0, the modem is USR Sportster 28.8k, and /etc/gettydefs at 19200 is

19200 # B19200 HUPCL IGNPAR ICRNL IXON OPOST ONLCR CS8 CREAD ISIG ICANON ECHO ECHOK ISTRIP IXANY TAB3
# B19200 SANE CS8 ISTRIP IXANY TAB3 HUPCL
#login: #19200

No changes were made to /etc/uucp/Dialers .

Over the weekend I raised -t from 60 to 1800. During the time I was connected, session disconnection worked properly, even after leaving the keyboard idle for 20 minutes.