telnetd deamon issue

[gab_in]

Hi,

One of our HP-UX Server (rx6600-ia64) is having problem with the telnetd daemon.If We try to do telnet from a different machine We get the follwing error. Can you please help on it.

Escape character is '^]'.
Local flow control off
telnetd: Telnet device drivers missing: No such device Connection closed by foreign host.

We have seen that there are around 40-50 telnetd daemons are running with owner root . Once we kill all of them and start the inetd daemon then it starts working. We would like to know why so many telnetd daemons are running and what is root cause of this problem.

Thanks in advance

[Mounaam]

Hi,

try to increase kernel parameters npty and nstrpty (via SAM) and create corresponding devices with insf.

For example:
# insf -e -n 120 -s 120

[VK2COT]

Hello,

A search of this Forum will reveal several
possibilities. This was discussed on many
occasions.

a) Corruption of devices.

Firstly, do some sanity checks. Telnet
requires two drivers to be installed
in the kernel: a master telm and as many
slave tels as are required by the
number of telnet connections.

In addition, at the file system level, telm
requires one device file - /dev/telnetm.

tels requires an nstrtel number of device
files in /dev/pts/t*

Each inbound telnet connection takes one
nstrtel kernel entry and one tels(7)
device file. The kernel entry and device
file should be released when the
telnet connection is closed.

Here is an example of telnet drivers and
device files:

# lsdev | grep tel
Character Block Driver Class
58 -1 telm strtels
61 -1 tels strtelm

Check the master driver's device file:

# ll /dev/telnetm
crw-rw-rw- 1 root sys 72 0x00003d Jan 27 2006 /dev/telnetm

# lsdev | grep 72
72 -1 clone pseudo

# lssf /dev/telnetm
streams cloneable pseudo driver telm /dev/telnetm

How many tels devices are available?

# ll /dev/pts/t* | wc -l
60

Possible solution at the console (do not log
in via standard remote session!):

# cd /
# rm /dev/pty/*
# rm /dev/pts/*
# insf -e
# cd /dev
# insf -d telm
# insf -d tels

b) Insufficient kernel parameters:

npty
nstrpty
nstrtel

c) For some HP-UX versions - missing patches.
For HP-UX 11.23 PA-RISC, patch HNE_35770 is
recommended.

At a quick glance, I did not see similar
patch for Integrity platforms.

Cheers,

VK2COT

[Vishwas Pai]

As replied over other replies, run "insf -e" to recreate DSFs should solve the telnet problem. But you may be left with some stale DSFs, which you need to identify and remove manually.

Sometimes these issues are reported when panic/TOC is involved. For 11.31 install the following patches to avoid this happing in such situations.

--vishwas

-
11.31 ioscan(1M) cumulative patch PHCO_37479
11.31 ioinit(1M) cumulative patch PHCO_37481
11.31 ioinitrc cumulative patch PHCO_37482
11.31 mksf(1M) cumulative patch PHCO_37484
11.31 sfd patch PHCO_37485
11.31 GIO cumulative patch PHKL_37458
11.31 dev_config cumulative patch PHKL_37459