Some Users Can't Telnet in

[Laurie_2]

Some of my users can't telnet
into the box but some can.
If I type "finger" the system
hangs. Yet the response time
in glance and top seems OK.

What would cause this. Here is my uptime:

9:36am up 18 days, 1:59, 60 users, load average: 1.74, 1.73, 1.69

I keep getting these messages
in syslog:

telnetd[24887]: getpid: peer died: Connection timed out

Laurie

[harry d brown jr]

Laurie,

What OS are you running, and is it up to date with patches?

Do you have an /etc/resolv.conf file? Basically, how are names being resolved?

What are your kernel parameters?

live free or die
harry

[Helen French]

Hi Laurie,

Check this out:

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=5b2a256206a8115c8f/screen=ckiDisplayDocument?docId=500000000092173

HTH,
Shiju

[Bill McNAMARA_1]

I'd check for zombie processes and the number of ptys defined.

sysdef

Also if it's specific to certain users, try to figure out if they're connecting from windows and using the [x] rather than Ctrl-] or quit to disconnect.

Also wouldn't be any hard to apply telnet patches..

Later,
Bill

[Uday_S_Ankolekar]

Hi,

Try changing these Kernel value
npty 600
nstrpty 600
nstrtels 600

This require reboot.

Ususally this error is due to abnormal Telnet termination.

Also check the nsswitch.conf and resolv.conf file in /etc to check how is host get resolved.
Following is the Tech doc for more info.
DocId:
KBRC00003896

Updated:
2/20/01 7:52:00 AM


PROBLEM

Remote PC clients (using X terminal emulator software) are unable to telnet to
hp9000. There are entries in syslog.log and OLDsyslog.log on the hp9000 that
are
as follows:

... telnetd[PID1]: ttloop: peer died: Connection timed out
... telnetd[PID2]: recv: Connection reset by peer

telnet using hpterms from other hp9000's to the affected hp9000 is not a
problem.

NOTE:
... telnetd[PID]: ttloop: peer died: Connection timed out
means the clinet system telnet-ing in 'died', or initiated a disconnect for
some reason.


RESOLUTION

Possible Solutions:

1. Are you telnetting in using hostname or ip? Do you get the same
delay when you telnet with hostname and/or ip?

a. If the delay is the same, look at /var/adm/nettl.LOG00 to see if this
log file got updated recently. If it was, this is an indication of a
duplicate IP address. Format the /var/adm/nettl.LOGXX file and look for
an indication of a duplicate IP in the output file:

# netfmt -Nlf /var/adm/nettl.LOG00 > /var/adm/nettl.out
# vi /var/adm/nettl.out
Pattern search on the string "dup" or "DUP"

b. If delay is longer telnet-ing in via hostname, look at name resolution
as the cause of this problem. Check for any DNS servers, as listed in
your /etc/resolv.conf file, as having named being unavailable. This may
be checked with nslookup:

# cat /etc/resolv.conf
domain rose.hp.com
nameserver 10.10.10.97
nameserver 10.10.10.98
nameserver 10.10.10.99

# nslookup
> server 10.10.10.97

Note: You may see a message such as:
"Specifying a server has overridden the switch policy order."
This is normal behavior.

> server 10.10.10.98

> server 10.10.10.99

Do this for the first 3 nameservers listed in the /etc/resolv.conf file.
To exit nslookup, enter a ^D.

If you find a nameserver that is not responding, try to find out if there
is a problem with the nameserver. Or, just remove that nameserver from
the /etc/resolv.conf file.

2. Drivers for PC NIC's:
What type of networkcards are in your PC's. We have had problems with
certain
PC vendors network cards who had driver software which was out of date from
other PC's with the same type of cards. Download and install the most recent
version of drivers for the PC network cards you are using and see if the
problem clears up.

3. Other questions to answer or actions to take if the above steps do not
fix the problem. Take note of answers to these questions and the output from
these actions if necessary to open a Response Center Call.

a. Try to reset the card using lanadmin:
# lanadmin -> lan -> reset

b. What kind of NIC is the hp9000 server using?
Get and install the latest patches and dependancies for the network
interface hardware you have.

c. Is there a problem with the cable/hub/switch?
Get the checklist for 100BT troubleshooting problems. It can be found
in the ITRC as RCEN KBRC00001359.

d. How many clients are experiencing the same problem?

e. Are there any errors in dmesg output of note?

f. Is telnet fast for hpterms, but takes a long time with other emulators?

g. Does the hp9000 have a graphics console? If yes, is it slow in getting a
graphics login using CDE or VUE or X-Windows/Motif window manager?

h. On the PC, do you use ReflectionX or Exceed or some other type of
terminal emulator or are you doing XDMCP logins to the hp9000 server?

-USA..

[James George_1]

Hi

another guess...check for the idle users who are there for long time and kill them . These users are occupying the tty's which makes new connections impossible...clear up some of the logins..

Rgds / James

[Laurie_2]

OK problem solved.

Our DSN stopped doing Reverse
Order Lookup which caused this
problem. I thought it was a
networking problem, but unix
gets blamed, oh well. Our networking person isn't sure
how to fix this DSN...

How we resolved the problem
was to edit our /etc/nsswitch.conf file.

We commented out the dsn part:

hosts: files [NOTFOUND=continue] # dns

Now it works fine.

We tested it by hard coding
the an ip address of a slow pc in /etc/hosts to see if that fixed the the speed problem with telnet and it did.

However, I didn't want to hardcode all
the IP addresses, so I took
out having my hp server go to
the dns and now let our nameserver in the resolv.conf
file do the work.

Makes sense? I'm not sure if
I am explaining it correctly
so please add to this if needed.
thanks,
Laurie

[Sanjay_6]

Hi Laurie,

Thanks for posting the results. you make perfect sense. We ourself had some DNS issues today. out system unable to resolve some ftp sites, till the times the DNS folks were working on the problem, we hardcoded the ftp sites ip to our /etc/hosts files, so we are still using DNS as out primary resolution, but it falls back to files in case it is unable to locate a dns entry.

Thanks