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Unable to telnet my host.

 
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Andrei Motorin
New Member

Unable to telnet my host.

I've never seen this before. Attempt to telnet my host returns:
telnet cray
Trying...
Connected to cray.
Escape character is '^]'.
telnetd: Telnet device drivers missing: No such device
Local flow control off
Connection closed by foreign host.

Rlogin and ftp are working fine. What could be a reason?

Thank you,
Andrei Motorin
13 REPLIES 13
Alex Glennie
Honored Contributor

Re: Unable to telnet my host.

Try this ?

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

Also look at increasing the kernal parameter nstrtel if need be.
Joseph Chakkery
Valued Contributor

Re: Unable to telnet my host.

Hello,

May be recInsf ???d tels reating ur telnet devices will solve the problem. This happened to me once after loading some patches. I did the following
$ Insf ???d tels
which create all telnet device files again.

Hope this helps u.

Regards
Joe.
Knowledge is wealth
Andrei Motorin
New Member

Re: Unable to telnet my host.

Thank you guys, but it doesn't help. I've recreated special devices but still obtain the same message.
Paula J Frazer-Campbell
Honored Contributor

Re: Unable to telnet my host.

Hi

Try stopping and starting inetd.

inetd -k ( kill)
inetd -c (reread /etc/inetd.conf)


HTH

Paula
If you can spell SysAdmin then you is one - anon
Andrei Motorin
New Member

Re: Unable to telnet my host.

More thanks to Alex! His hint about maximum of telnet connections was really helpful!

How can I add points for his answer?

Andrei Motorin
Vincent Farrugia
Honored Contributor

Re: Unable to telnet my host.

Email him, tell him to post an answer, and assign points to that.

Simple isn't it? :-)

Vince
Tape Drives RULE!!!
Alex Glennie
Honored Contributor
Solution

Re: Unable to telnet my host.

are you saying increasing the nstrtel to more than 60 resolved your pronblem then ;)
Eric Guerizec
Frequent Advisor

Re: Unable to telnet my host.

Hello!

I have the same problem with telnet. When I try to connect to the server, I've got the message :
telnetd: Telnet device drivers missing: No such device
Kernel parameters are :
npty 512
nstrpty 60
nstrtel 60

Some messages say to increase nstrtel but I only have 14 process telnetd running on this server !!!!

Alex says to try :
- rm /dev/pts/t*
- rm /dev/pty/t*
- cd /dev
- insf -e
- insf -d telm
- insf -d tels
I don't try this because I don't know If "rm" will destroy all the active connections.

Does anybody can help me?

Eric
Paula J Frazer-Campbell
Honored Contributor

Re: Unable to telnet my host.

Hi

Try stopping and starting telnet.

inetd -k ( kill)
inetd -c (reread /etc/inetd.conf)


Paula
If you can spell SysAdmin then you is one - anon
Bill Hassell
Honored Contributor

Re: Unable to telnet my host.

In HP-UX 11.x, all telnet connections use the streams-based device files in /dev/pts/t# and need a slot from the nstrtel kernel parameter.
Each regular inbound telnet connection needs to be considered in nstrtel, including DTC so-called nailed ports in /etc/ddfa/dp.

To calculate the number, you need to set nstrtel to add up all telnet connections from PCs, other systems, DTCs with and without nailed ports, and set nstrtel large enough to cover all of them. Either use SAM or, if you increase the kernel parameter manually, call insf afterwards to create all necessary device files.

The only exception are for DTC outbound ddfa printer connections which still require a slot in npty. Rlogin uses nstrpty; terminals and modems directly attached to serial ports on the system also continue to use npty.

Since more and more subsystems are using streams-based drivers, the simplest solution is to make npty = nstrpty = nstrtel, and if you use SAM, all the needed device files will be created.

Note that if root accidently removes a device in the middle of chain (see bottom of man page: man 7 pty), then the search for an available device file terminates. Removing them and then using insf to recreate them will solve that problem. Note that this should be done from the console, ideally in single user mode since you are removing all the network connection files.


Bill Hassell, sysadmin
Eric Guerizec
Frequent Advisor

Re: Unable to telnet my host.

Thank you, Paula & Bill
I wouldn't have to take again the message of Andrei because now I can't assign points to you. Aaargh!!!
Sorry!
Andrei Motorin
New Member

Re: Unable to telnet my host.

No problem, Eric.

I can do it for you :)
Eric Guerizec
Frequent Advisor

Re: Unable to telnet my host.

Cool!
5 points to Paula and 7 to Bill.
ciao :)