topic Re: Find DHCP Server from client in Operating System - HP-UX

Find DHCP Server from client

Karthik S S — Mon, 01 Dec 2003 16:19:01 GMT

How can a DHCP client can determine from which DHCP server has it got the IP address??
Is there any command for that??

Pl. help

Thanks,
-Karthik S S

Re: Find DHCP Server from client

John Dvorchak — Mon, 01 Dec 2003 17:08:51 GMT

To the best of my knowledge, the client will send a dhcp broadcast and the server, hearing the broadcast will respond. Now this assumes that your routers will pass dhcp broadcasts across subnets. If it is not working then check with the network folks and see if they have shutdown broadcasts. If they have and won't re-enable them you will need a dhcp server on the same subnet as your dhcp clients.

Re: Find DHCP Server from client

John Dvorchak — Mon, 01 Dec 2003 17:13:55 GMT

Boy did I read your message wrong and gave a completely off target answer. Sorry about that.

It depends on the client, in Windows it is ipconfig /all if you are using HPUX I think all you can do is run arp -a and look for the server.

Maybe someone else has a better answer.

Re: Find DHCP Server from client

Karthik S S — Mon, 01 Dec 2003 17:29:55 GMT

Well, what I really wanted to do from my DHCP is client is to find out which DHCP server has acutually leased an IP address to me ...!!! With Windows as you said it is possible to find that out using ipconfig /all.

I wonder if there is any file/command using which we can find this out...

-Karthik S S

Re: Find DHCP Server from client

Hazem Mahmoud_3 — Mon, 01 Dec 2003 18:20:54 GMT

Try the following:
/usr/sbin/dhcptools -t ct=20
I'm not sure if this will only work on the DHCP server or if it will also work on the DHCP client. What it does is it traces packets going back and forth to the dhcp server and places it in the /tmp/dhcptrace file. Hope that will help.

-Hazem

Re: Find DHCP Server from client

Helen French — Tue, 02 Dec 2003 11:13:30 GMT

Did you check the 'dhcpclient' command? If you enable DHCP, you can make use of this command to get DHCP details. Also check the file /etc/dhcpclient.data

http://www.docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B9106-90008/B9106-90008_top.html&con=/hpux/onlinedocs/B9106-90008/00/00/81-con.html&toc=/hpux/onlinedocs/B9106-90008/00/00/81-toc.html&searchterms=dhcpclient&queryid=20031202-091025

Re: Find DHCP Server from client

Karthik S S — Tue, 02 Dec 2003 11:55:37 GMT

Sorry about that. I didnt try yesterday.

I created a VIF using,

ifconfig lan0:1 plumb
ifconfig lan0:1 up

Configured lan0:1 as DHCP client in
/etc/rc.config.d/netconf

Restarted the network daemons. But lan0:1 still doesnt obtain any lease. I also tried,

/usr/lbin/dhclpclient -b lan0:1

Is this the right way to configure a DHCP client??

Thanks
Karthik S S

Re: Find DHCP Server from client

PVR — Wed, 03 Dec 2003 02:33:18 GMT

this link may be helpful

javascript&colon;openExternal("http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90685/B2355-90685_top.html&con=/hpux/onlinedocs/B2355-90685/00/00/56-con.html&toc=/hpux/onlinedocs/B2355-90685/00/00/56-toc.html&searchterms=configuration%7cdhcp&queryid=20031110-165843")

Re: Find DHCP Server from client

Karthik S S — Wed, 03 Dec 2003 14:04:40 GMT

Thanx .. but, It doesn't discuss about configuring the client.

-Karthik S S

Re: Find DHCP Server from client

Karthik S S — Fri, 05 Dec 2003 17:08:51 GMT

HOW DO I CONFIGURE HP-UX AS A DHCP CLIENT???

Pl. help :-(

-Karthik S S

Re: Find DHCP Server from client

James A. Donovan — Fri, 05 Dec 2003 17:20:56 GMT

Check out this link on how to reconfigure for DHCP.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=91624

Re: Find DHCP Server from client

Hazem Mahmoud_3 — Fri, 05 Dec 2003 17:44:21 GMT

Here is the documentation on configuring DHCP for HP-UX:
http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90775/B2355-90775_top.html&con=/hpux/onlinedocs/B2355-90775/00/00/14-con.html&toc=/hpux/onlinedocs/B2355-90775/00/00/14-toc.html&searchterms=dhcp&queryid=20031205-153920

Also take a look at the following forum:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=140537