Telnet service not working

[Jes Yu]

I just installed new OS HP-UX B11.11 on C3700, telnet service is not working.
1. In /etc/services file, line exists:
telnet 23/tcp #Virtual Terminal

2. In /etc/inetd.conf file, line exists:
telnet stream tcp nowait root /usr/lbin/tcpd /usr/lbin/telnetd telnetd

3. I typed: /etc/inetd -c

4. When I typed: netstat -an | grep LISTEN | grep 23
nothing displayed.
It should have "tcp 0 0 *.23 *.* LISTEN" returned.

Any one know what did I wrong? Thank you!

Jess

[Andy Bustamante]

>>>Any one know what did I wrong? Thank you!

Posted an HP-UX issue in the OpenVMS forum.


Andy

[Jes Yu]

Shoudl I post it somewhere else?
Thanks!

[Steven Schweda]

> Any one know what did I wrong?

You mean other than asking an HP-UX question
in a VMS forum?

> [...] telnet service is not working.

Did you actually try it? What happened?

> telnet stream tcp nowait root /usr/lbin/tcpd /usr/lbin/telnetd telnetd

Around here:

dy # grep telnet /etc/inetd.conf
telnet stream tcp nowait root /usr/lbin/telnetd telnetd

What's "/usr/lbin/tcpd"?

> It should have [...]

Yup:

dy # netstat -an | grep LISTEN | grep '.23 '
tcp 0 0 *.23 *.* LISTEN

[Steven Schweda]

> Shoudl I post it somewhere else?

Next time:

http://forums.itrc.hp.com/service/forums/familyhome.do?familyId=117

Some alert moderator will probably move it
eventually.

[Jes Yu]

When I typed:
netstat -an | grep LISTEN | grep '.23 '

nothing happen. No return at all.

telnet/tcp service unknown.

[Steven Schweda]

> When I typed:
> [...]

Yeah, I got that. I was wondering whether
you had actually tried a "telnet" command.

> telnet/tcp service unknown.

Huh?

Around here, copy+paste makes it very easy to
show actual commands with their actual
output. My psychic powers are too weak to
tell me how you got that.


> What's "/usr/lbin/tcpd"?

Still wondering...

Did you look at the difference between your
/etc/inetd.conf and mine?

[Jes Yu]

"/usr/lbin/tcpd" does not exist. Might be the problem?

where is your /etc/inetd.conf ?
Thanks.
Jes

[Steven Schweda]

> "/usr/lbin/tcpd" does not exist.

So why did you specify it in your
/etc/inetd.conf file?

> Might be the problem?

Duh, may be.

> where is your /etc/inetd.conf ?

On my disk. Where's yours? Did you read
any of those replies?

> Jul 28, 2009 16:42:54 GMT
> [...]
> Around here:
>
> dy # grep telnet /etc/inetd.conf
> telnet stream tcp nowait root /usr/lbin/telnetd telnetd
> [...]

[John Poff]

Hi,

Have you checked your syslog (/var/adm/syslog/syslog.log) file after you did the 'inetd -c' command? If inetd doesn't like your telnet configuration, you might find some clues there.

JP

[Jes Yu]

mine /etc/inetd.conf:
telnet stream tcp nowait root /usr/lbin/tcpd /usr/lbin/telnetd telnetd

if /usr/lbin/tcpd does not exist, that might be the problem. I will copy one from anothe HP box and test.

syslog message: telnet/tcp service unknown

[Steven Schweda]

> I will copy one from anothe HP box and test.

If you can't find one, let me know, and I'll
show you mine again (and again, ...)

[Jes Yu]

Steve, you are very sweet. I copied one (/usr/lbin/tcpd) from anothe HP box, reboot it. Not working, :-(.

and ftp, rlogin... not working. Ping and NFS work.
some patch missing? Thanks!
Jessica

[Mel Burslan]

Open a terminal windows to this box and run

tail -f /var/adm/syslog/syslog.log

go to another system and telnet to this system. At this point, do you see anything coming to the syslog ? There should be some words written into the syslog and to your screen at the same time, regarding a telnet connection attempt. If you are not getting these notifications, I would suspect your firewall blocking the request from coming to your server. If this is the case, talk to your network or firewall administrators.

[Jes Yu]

tail -f /var/adm/syslog/syslog.log

I got "services unknown"

No firewall blocked at all. It is within the company. My system adminstrator checked it.

[Steven Schweda]

> [...] I copied one (/usr/lbin/tcpd) [...]

Sorry. I assumed that you'd be copying the
right line to put into your /etc/inetd file,
not the file you didn't need and shouldn't
have been specifying there.

At the risk of repeating myself (yet again):

> Did you look at the difference between your
> /etc/inetd.conf and mine?

> Jul 28, 2009 16:42:54 GMT
> [...]
> Around here:
>
> dy # grep telnet /etc/inetd.conf
> telnet stream tcp nowait root /usr/lbin/telnetd telnetd
> [...]

[Jes Yu]

on my box,
# grep telnet /etc/inetd.conf
telnet stream tcp nowait root /usr/lbin/telnetd telnetd

which is exactly the same as yours.

[John Poff]

Ok, here is a long shot. Do you have telnet listed in your /etc/services file? I wouldn't think that would stop it, but who knows?

grep telnet /etc/services
telnet 23/tcp #Virtual Terminal Protocol


JP

[Steven Schweda]

> 2. In /etc/inetd.conf file, line exists:
> telnet stream tcp nowait root /usr/lbin/tcpd /usr/lbin/telnetd telnetd

> on my box,
> # grep telnet /etc/inetd.conf
> telnet stream tcp nowait root /usr/lbin/telnetd telnetd
>
> which is exactly the same as yours.

Did it change? If so, did you repeat step 3
("3. I typed: /etc/inetd -c") after the
change?

And if it didn't change, what's the story?
I'm confused.

[Steven Schweda]

> Ok, here is a long shot.

I'll say. Especially, given this:

> Jul 28, 2009 16:08:53 GMT
> [...]
> 1. In /etc/services file, line exists:
> telnet 23/tcp #Virtual Terminal

> I wouldn't think that would stop it,

I wouldn't, either.

> but
> who knows?

Someone who's tried it might.

[Jes Yu]

sorry for the confuse. In the title, I was wrong for #2. It should be
2. In /etc/inetd.conf file, line exists:
telnet stream tcp nowait root /usr/lbin/telnetd telnetd

[Jes Yu]

for some reasons, some services don't start. login, rlogin, ftp, telnet... not working.
ping and NFS work.
strange!

[Mel Burslan]

>tail -f /var/adm/syslog/syslog.log

>I got "services unknown"

do you see services unknown in the syslog file when you try to telnet from another box ?

[Jes Yu]

It was caused by NIS. I fixed it by the following steps:
1. cp /etc/nsswitch.nis /etc/nsswitch.conf
2. vi /etc/nsswitch.conf
3. remove all lines, but line:
services files
4. inetd -c

Thanks for eveyone's help.

Jessica

[Steven Schweda · Accepted solution]

> It was caused by NIS.

I don't recall anyone mentioning that NIS was
in use.

> Any one know what did I wrong?

Only the more powerful psychics knew what you
did, let alone what you did wrong.

> I fixed it by the following steps:
> [...]

Some people merge the "services" data from
all their NIS client systems into the master
NIS "services" source file. Unless there's
a conflict (unlikely, I'd guess, but I also
don't know where you use NIS), that method
obviates problems like this.