Discover telnet client IP address

[Michael Poland_3]

I'd like to set the value of DISPLAY to be the client's IP address as opposed to the name returned by the DNS.
(Our DNS seems to be having some problems returning the correct name. When I issue who -um from a specific client PC it cycles through 3 different names and we're trying to get that issue sorted too)
Any suggestions greatly appreciated.

[Steven E. Protter]

If the host is hpux, try this:

last -R

That will provide the hostname of the telnet and other protocol clients.

Also:
enhance your logging:
inetd -l

There will be information there mostly by ip address.

SEP

[Michael Poland_3]

Forgot to mention platform: hp-ux 11.0

Tried the last command, but it too returns host names not ip addresses.

I read another thread where the contributor said that everything gets resolved back to the DNS name. Is there no way to avoid this and get the IP address (other than disabling DNS)?

[Steven E. Protter]

Last command does turn up the hostnames.

These can be translated by reverse lookup to IP addresses with the nslookup command. See the man for that one.

Also, the times on the last command will correspond to data in the syslog which will be exclusively IP addresses.

Yes, you may actually have to do a little work to get the information, but your system records all you need to do the job.

SEP

[Muthukumar_5]

Your problem is because of your hostname being displayed on who -um command output.
We can get reverse lookup of ip-address with getip / nslookup / nsquery / dig command.

I prefer getip command for this.

export DISPLAY=getip `who -um | awk '{ print $9 }'`.0

HTH.

[Vishwas Pai]

As the initial post said, they have some
problem with DNS and hence he wants to use
only ip@.

My question is will getip again contact
DNS for get the ip@ of the hostname ?

-vishwas

[Ralph Grothe]

As it looks the getip is a simple wrap of the gethostbyname() syscall.
In the syscall's manpage it says that it will respect the hosts entry in /etc/nsswitch.conf.
So if his nsswitch.conf holds something like:

hosts: files [NOTFOUND=continue] dns

it will do namelookup by first parsing /etc/hosts on the localhost, where it should find the IP address.

Alternatively you could use nsquery like

DISPLAY=$(nsquery hosts $(who -mu|awk '{print$NF}')|awk '$1~/ddress/{print$NF}'):0

[Ivajlo Yanakiev]

Hi,

If you have problems whit your DNS you must corect them. HPUX work fine olny if DNS is ok. Telnet,sam,X and Software agent need
ip resolve.
If you have problem with DNS use /etc/hosts file.
File that is good to check.

/etc/nsswitch.conf
/etc/resolve.conf
/etc/hosts


if you can not find /etc/nsswitch.conf
copy /etc/nsswitch.files /etc/nsswitch.conf

[Michael Poland_3]

Thanks for all your replies. We've deep clensed the DNS now and aged out all the duff records.

Just one point, I changed the inetd configuation (netdaemons) to start inetd with the -l option then executed inetd -c but still do not see detailed loging in syslog. Do I need to do a reboot to enable the change?

[Ivajlo Yanakiev]

Do not reboot.
Only windows need reboot :) you now :)
if you need to restart some services go to
/sbin/init.d/
and

./someservices stop
./someservices start

[Dietmar Konermann · Accepted solution]

Michael,

in Windows reboot - on Unix be root. ;-)

Simpy issue "inetd -l" to toggle logging on/off. You see the effect immediately in syslog.log.

Best regards...
Dietmar.

[Michael Poland_3]

Thanks all