UNIX for Dummies Questions & Answers

Hi there,

I am wondering if by logging in to a unix system, if it is possible to get the IP address of the machine I am connecting FROM.

I know how I can do this using the name server, but is this possible without a host lookup?

Thanks,

-ghoti

If you were connected via ssh/telnet running "netstat -n -e" from the server would show what user ids and ip addresses are connected to the server.

"netstat -e" would show user names and hostnames connecting to the server.

The ipaddress and user details will also go into one of the system's log files although I you might not have access.

It may sound silly but why do you need to know this?


Andy Hibbins

Thanks for the help Andy, but I had got that far already.

The problem is this:

we are working using a unix box, accessed from several windows systems, usually running Hummingbird Exceed. As some of the technicians need to access the server from many locations worldwide, I need to set the $DISPLAY variable using an IP address rather than a hostname, as not all the IP's are in the DNS.

I had initially thought that I could use 'netstat |grep X' to isolate the connections using an Xserver, then do the same using netstat -n to get the ip number, but this fails with multiple connections, as it is very difficult to differentiate using a script.

Cheers for the help tho...

-ghoti

On my systems, <B>netstat -en </B> provides the kernel level user of the sockets (tcp, unix) , not the application level user (i.e john, harry, sally, root).

Working to automatically set the X display parameter is normally not performed with shell utilities such as netstat; but passed as environmental varialble during remote login. This is a function of the remote login protocol.

Some versions of telnet automatically set the DISPLAY variable, so that when you login remotely, DISPLAY is set and exported for X to use. However, your problem seems to be that this works for you already, but you have DNS issues.

I think it is possible to have the remote login session pass the IP| address in the DISPLAY environment variable. There is no reason to only pass the FQDN to $DISPLAY.

As a matter of fact, if you have your remote users set the IP address in their HOSTNAME environment variable before remote login (or do this is the login script); then you will not have to worry about the DNS issues.

HOSTNAME = 111.222.333.444

DISPLAY = $HOSTNAME:0.0

Thsi is a good option, but it requires special settings on all the clients, rather than just one script..

Thanks anyway, and I'll keep looking, if I find it, I'll post my solution,

-ghoti

have you tried #who -a ???

Thanks for the suggestion, but this seems to use the host lookup again, I am really looking for just the IP information.

Cheers anyway!