topic ssh server slow in Operating System - HP-UX

ssh server slow

letters — Wed, 04 May 2011 07:53:23 GMT

Hello,

When i connect to a HPUX11.31 in ssh ; i type my login and i must wait 30-40 seconds before to see appear the prompt of password !
What' s the problem ?
Thanks

Re: ssh server slow

sangilak — Wed, 04 May 2011 08:06:09 GMT

Hi,

Not sure which version of SSH you have currently installed, but I remember to have read somewhere that the latest version 5.60 addresses some slow loging issues.

It can be downloaded from:
https://h20392.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=T1471AA

Hope that helps,

sangilak

Re: ssh server slow

letters — Wed, 04 May 2011 08:43:40 GMT

I think that it's a network problem because i have also the same problem with sftp

Re: ssh server slow

Viktor Balogh — Wed, 04 May 2011 10:54:13 GMT

I bet you have a large wtmps file, the solution is to purge that file:

# > /var/adm/wtmps

Now ssh should work fine. It is a known bug...

Re: ssh server slow

Viktor Balogh — Mon, 11 Jul 2011 15:51:38 GMT

"HP-UX Secure Shell Software - Logins Slower after Update to Version A.04.70.010
ISSUE:
User was running HP-UX Secure Shell-A.04.30.007 and all was working OK. He updated to a more current version (A.04.70.10) and now his logins take 10-15 seconds to complete. The delay appears after entering the password.

SOLUTION:
The newer version of the ssh daemon (/usr/bin/sshd) will read the entire file /var/adm/wtmps if it exists. Since this file grows without bound, it can become exceeding large and cause delays in the login process.

The man page for wtmps states:

Note that wtmps and btmps tend to grow without bound, and should be checked regularly. Information that is no longer useful should be removed periodically to prevent the file from becoming too large. Also note that wtmps and btmps are not created by the programs that maintain them. Thus, if these files are removed, login record-keeping is turned off."

see this thread:

http://h30499.www3.hp.com/t5/System-Administration/SSH-Authentification-very-slow-on-HPUX-11-31/m-p/4361622#M346130

Re: ssh server slow

Steven Schweda — Wed, 04 May 2011 12:09:01 GMT

> [...] HPUX11.31 in ssh [...]

ssh -V

Actual output from "uname -a" wouldn't hurt,
either.

> What' s the problem ?

Is this a new problem where things have
worked properly before?

> I think that it's a network problem because
> i have also the same problem with sftp

SSH and SFTP are not different enough that
that tells you anything. If other,
_different_ services (like, say, FTP or
Telnet), also see a delay, then you may have
a DNS problem. A Forum search for keywords
like:
ssh slow dns
should find many old threads which describe
the common DNS problem, and how to fix it.

Re: ssh server slow

uz — Wed, 04 May 2011 12:14:28 GMT

I purged wtmps and wtmp but it's the same

Re: ssh server slow

uz — Wed, 04 May 2011 12:21:20 GMT

[root@X-4 /opt/mozilla]# ssh -V
OpenSSH_4.5p1+sftpfilecontrol-v1.1-hpn12v14, OpenSSL 0.9.7l 28 Sep 2006
HP-UX Secure Shell-A.04.50.011, HP-UX Secure Shell version
[root@X-4 /opt/mozilla]# uname -a
HP-UX X-4 B.11.31 U ia64 069218587 unlimited-user license

Re: ssh server slow

Steven Schweda — Wed, 04 May 2011 13:25:25 GMT

> HP-UX Secure Shell-A.04.50.011[...]

Not the latest version, is it? (But that
should not be the problem here.)

> Is this a new problem where things have
> worked properly before?

Still wondering.

> [...] A Forum search [...]

Did you look? On the SSH server:

nslookup

Re: ssh server slow

Bob_Vance — Wed, 04 May 2011 16:19:35 GMT

Be sure that the ipnodes entry is same as the hosts entry in

/etc/nsswitch.conf

## grep -e host -e node /etc/nsswitch.conf
hosts: files [NOTFOUND=continue UNAVAIL=continue] dns
ipnodes: files [NOTFOUND=continue UNAVAIL=continue] dns

bv

Re: ssh server slow

uz — Thu, 05 May 2011 06:34:44 GMT

I added "[NOTFOUND=continue UNAVAIL=continue] dns" to the line "ipnodes: files"
but always slow connexion

And as answer to Steven
> Is this a new problem where things have
> worked properly before?

This server has been installed by a person who is gone and i haven't the history of the instal

Re: ssh server slow

Steven Schweda — Thu, 05 May 2011 09:40:42 GMT

> And as answer to Steven
> [...]

One answer, more than one question. I'll try
one more time.

> [...] If other,
> _different_ services (like, say, FTP or
> Telnet), also see a delay, then you may have
> a DNS problem. A Forum search for keywords
> like:
> [...]

> > [...] A Forum search [...]
>
> Did you look? On the SSH server:
>
> nslookup

Re: ssh server slow

Bob_Vance — Mon, 11 Jul 2011 15:50:33 GMT

Oooops, my bad.

It would help if I read the orignal problem description correctly!

The slowness is *after* login prompt,
so it's probably not a usual DNS issue.

Does the problem occur when you try to ssh into the box from another login on the same box (ie, to itself)?

You can start a temporary sshd in debug mode on a different port to see what sshd and is doing.

With ssh -v from the source and the debugging sshd, you should be able to see exactly what they are both doing during the delay.

See Victor's and my suggestions in this thread:

You can watch both the incoming
http://h30499.www3.hp.com/t5/General/ssh-stopped-working-after-depo-patch-update-on-hp-11-23/m-p/4783582#M147810

Re: ssh server slow

rmueller58 — Thu, 05 May 2011 13:15:45 GMT

How is response on the console?

Connection time delay can be caused by many things.. Network traffic and utilization is a big culprit in delays as well. I see guys posting messages regarding things to look at on the UX box, and if the system was working OK up to a certain point and then doesn't.

on the UX box check top and see what your system utilization is doing, memory can be a problem. When we initially purchased one of our systems it was undersized in terms of RAM. We bumped the RAM and the problem went away.

Rule out the UX box, by checking the things being mentioned by others. May sure you have your kernel and wtmp settings correct.

That said, since, that problems with connection for us has been generally directly attributed to changes made on the DNS, network and traffic.
Content Filters, Someone downloading or streaming a video on a segment of the network, can slow connection time dramatically because of saturation.

my 2 cents.

Re: ssh server slow

Bob_Vance — Thu, 05 May 2011 13:44:47 GMT

Wait...

Why are you being asked for a login id?

Are you coming from another Unix/Linux box or are you using a SSH client, like 'Putty', from a Windows box?

What command are you using on the incoming and what version of ssh is it?

Please give us also HPUX sshd version:

## /usr/sbin/sshd -d 2>&1 | grep vers
debug1: sshd version OpenSSH_5.1p1+sftpfilecontrol-v1.2-hpn13v5 [ HP-UX Secure Shell-A.05.10.007 ]

bv

Re: ssh server slow

uz — Fri, 06 May 2011 08:10:59 GMT

In fact, there isn't only the ssh connexion who is long : for example if i type :

[root@RX-2#swlist
I have :
#Initializing...
#Contacting target "RX-2"...

and the message remains for at least 2 minutes
before making the list !

I think that i go to reinstall this machine, somebody have the installation guide please

Re: ssh server slow

Bob_Vance — Fri, 06 May 2011 09:59:53 GMT

show us

# cat /etc/resolv.conf
# grep -v ^# /etc/hosts
# grep -v ^# /etc/nsswitch.conf
# time nslookup rx-2

You still have not shown us the ssh & sshd versions.

who installed this system?
when?

show us

# swlist -l bundle | grep -e QP -e HWE
# swlist | grep Secure

bv

Re: ssh server slow

letters — Fri, 06 May 2011 12:25:27 GMT

thanks for all it was a dns problem !

Re: ssh server slow

Steven Schweda — Fri, 06 May 2011 17:56:42 GMT

> [...] it was a dns problem !

It often is.

It might be helpful to some future reader if
you took a minute to explain how you found
the problem, and what the fix was.