Find DHCP clients in different VLANs


I have some problem, so i would your suggest to help me in this regards.

How do i solve this problem that the network is already configured and up and running but it dhcp, dns and gateway is unknown, i can find these but i can’t find the devices which are using dhcp ip and which devices are using static ip because i want to configure more 4 vlans on each switch, so i don’t want to make pool of dhcp ip to each subnet, so in this case how can i create vlans which gets it ips from dhcp without any problem (looping, downtime and or ip conflict.

Please find the attached diagram for your kind information. If my problem solve then i will be your permanent student. I am looking forward to hear from you soon. Thanks in advance.

Hi Nasratullah,

I just moved this question from our feedback board to the forum here. The feedback board is only for new ideas/suggestions or bugs.

Let’s see…

If you want to solve this using your router or switches you could try this:

To find your DHCP clients, you should check your DHCP server and look at the DHCP bindings:

The show ip dhcp binding command gives an overview of all DHCP clients. To find the static IP devices that use a default gateway, you could check the ARP table of the router which is the default gateway for your clients.

Do a show ip arp to see the IP addresses that the router uses. Compare it with your DHCP binding, and you’ll know which ones are using a static IP address.

You’ll need a subnet for each VLAN. Since each VLAN is a broadcast domain, normally you’d need a DHCP server for each VLAN. However, you can use the DHCP relay feature to use a central DHCP server for multiple VLANs:

Hope this helps!