show IP address

[peterchu]

I have two hosts ( host A and host B ) , when a user rlogin from host A to host B , at host B side use "who" command can only show the remote host name ( host A ) but can't show the user IP address , could suggest how to know the IP address? thx

[Mel Burslan]

Normally "who" command when run without any options, do not display neither the hostname nor the IP address of the connection a user is coming from. To display the host information, command must be used with "-R" switch and this switch by default uses the function gethostbyaddr() and as long as it does not error out, it lists the name of the host next to the login information.

to obtain IP address instead of the hostname, is totally dependent on your processing of this information on the "who -R" output.

some construct like this may give you the result you are looking for:

who -R | while read id tty mon day time host
do
h=`echo $host | cut -d"(" -f2 | cut -d")" -f1`
ip=`nslookup $h | grep Address | cut -d: -f2`
echo "${id}\t${tty}\t${mon}\t${day}\t${time}\t${ip}"
done


Hope this helps

[peterchu]

thx reply,

I can see the ip address of local user login , but can't see the remote user ( by rlogin ), could suggest how to see it ? thx

[Rick Garland]

The'who -um' will show who the user is, where they logged in from, what the IP address is.
If DNS resolution is in play, then you will see the host name as resolved by DNS.

[Animesh Chakraborty]

HostB#getip Host A

[Deepak Kulkarni]

Hi Peter,

Run "who -u" command


Regards
Deepak

[Devesh Pant_1]

Peterchu,
normally I use the who -R command to get the IPs

thanks
DP

[Muthukumar_5]

You can get IP-Address,

remsh -l user HostB -n "who -um | awk '{ print $NF }' | xargs getip"

hth.

[prashanth_14]

$who -u
Above command should provide you required details.

[Bill Hassell]

Neither who nor the w command offer an IP address option. Technically, these commands only see an IP address but they try to be 'friendly' and translate the IP address into a real name. So you'll have to script a reverse loolkup by supplying the hostname and asking nslookup to return the IP.