Thread: How to trace your dhcp server ip address

Hello all,

I got a network with isp router, wireless access point, servers and 24 port switch. All of them got dhcp server running and i need to find out who is giving out IP address to clients?

run the following command on one your client systems

Code:

grep dhcp-server-identifier /var/lib/dhclient/dhclient.leases

Originally Posted by ananth_ak

run the following command on one your client systems

Code:

grep dhcp-server-identifier /var/lib/dhclient/dhclient.leases

it worked but with different file in /var/lib/dhcp3/ directory. I got eth0 and wlan0 files in those directory and it gave me ip of dhcp server. thank u!

FYI, you can also use the tcpdump command as follows:

Code:

 tcpdump -i eth0 port 67 or port 68

And get an IP using dhcp

Code:

dhclient eth0

And there is dhcpdump too - dhcpdump: Monitor DHCP Traffic For Debugging Purpose

/Closed.