topic Re: login prompt via telent slow in Operating System - HP-UX

login prompt via telent slow

Joe Milici — Tue, 27 Apr 2010 13:08:18 GMT

I have an HP-UX 11 v3 system with no users on it. It is being accessed across the WAN via telnet and the login prompt is taking an extended period of time to appear. If I telnet to the MP it returns a login instantly. I rebooted the server but the same issue is occuring. Is there a file that needs to be truncated or any other suggestions would be appreciated.

Re: login prompt via telent slow

Bill Hassell — Tue, 27 Apr 2010 14:51:26 GMT

If the delay is 30,60 or 90 seconds, then this is a very common problem with name resolution. telnet (which is strongly recommended to be replaced by ssh) wants to aythenticate the IP address of the incoming user, typically a PC. But the PC's address is not in /etc/hosts nor is it in DNS or NIS. The solution is to change /etc/nsswitch.conf to resolve addresses from /etc/hosts first, then look at DNS or NIS, something like this:

hosts: files [NOTFOUND=continue UNAVAIL=continue] dns
ipnodes: files [NOTFOUND=continue UNAVAIL=continue] dns

Then add the PC's IP address (as seen by HP-UX) and a dummy name to /etc/hosts and the delay should disappear. Note that is the WAN goes through a VPN or similar appliance, the PC address seen by HP-UX may be something else. Use the command:

who -muR | awk '{print $NF}'

to see what your HP-UX system is seeing as the incoming IP address.

Re: login prompt via telent slow

Joe Milici — Tue, 27 Apr 2010 14:57:39 GMT

Thanks for the info. I am somewhat skeptical because if this was an issue from day one I would suspect name resolution could be an issue but it was working perfectly and the telnet to the maintenance processor is working as expected so I am not convinced this is the problem.

Re: login prompt via telent slow

Steven Schweda — Wed, 28 Apr 2010 02:49:09 GMT

First, a Forum search for keywords like, say,
slow telnet
should find many similar threads, and even
some potentially useful explanations of
common problems, and, even more amazing, an
occasional solution.

> [...] DNS [...]

> [...] so I am not convinced this is the
> problem.

Nor am I, but there's a simple test (as seen
in some of those old discussions). On the
server system (after you do get connected),
try:

nslookup client_IP_address

If that's suspiciously slow, then that could
account for the problem.

Note that normal/forward DNS resolution
(name-to-address) can be working fine, but if
reverse resolution (address-to-name) is bad,
then you can get this kind of sloth when
trying to talk to a server program which
wants to know/verify your host name.

> Is there a file that needs to be truncated
> [...]

I've never had this problem, so I never
remember the details (and I might not
remember them, anyway) but you should be able
to find that in one (or more) of those old
Forum discussions where reverse DNS was not
the problem. (But it often is.)

Re: login prompt via telent slow

Dennis Handly — Wed, 28 Apr 2010 06:55:03 GMT

>Is there a file that needs to be truncated

If it isn't the lookup problem mentioned above, there have been some threads where the sizes of /var/adm/wtmp* grows too large and slows things down.

Re: login prompt via telent slow

Steven Schweda — Wed, 28 Apr 2010 14:22:04 GMT

> Thanks for the advice

Future Forum users (those who _do_ try to use
the Search feature) might be interested in
learning whether (and, if so, how) you
resolved your problem.

Re: login prompt via telent slow

Joe Milici — Wed, 28 Apr 2010 16:26:13 GMT

The issue was related to a bad DNS entry in resolv.conf. Once I put the corrected addresses into the file, I stopped and started the inetd process and response time is perfect. Thanks to all for your responses.