Notice that this regards DHCP servers and not relays.
These are some notes for showing the DHCP leases issued out by a FortiGate firewall.
One thing to consider is multiple pools can be configured for multiple networks at a time. So, don’t be destroying the addresses on all of the networks with what’s learned here.
Listing Leases
The command below will list all leases handed out by the DHCP server on the FortiGate.
execute dhcp lease-list all
Below is the output of the command. This will show the following data related to the DHCP pool hosted by the FortiGate firewall. This will show the following information.
- Interface/Pool Name
- Lease IP
- Leased MAC Address
- Hostname
- VCI
- SSID
- AP
- Server-ID
- Lease Expiry
www-dmz
IP MAC-Address Hostname VCI SSID AP SERVER-ID Expiry
172.16.100.5 00:B0:D0:63:C2:26 1 Mon Jul 24 12:11:45 2023
home-lab
IP MAC-Address Hostname VCI SSID AP SERVER-ID Expiry
192.168.10.6 00:B0:D0:63:C2:27 tl-app-01 2 Mon Jul 24 04:09:31 2023
192.168.10.10 00:B0:D0:63:C2:28 tl-pi-01 2 Mon Jul 24 10:52:48 2023
One interface or pool can be listed as well by specifiying its name. This will list all of the needed information related to it.
execute dhcp lease-list home-lab
The output can be shown below.
home-lab
IP MAC-Address Hostname VCI SSID AP SERVER-ID Expiry
192.168.10.6 00-B0-D0-63-C2-27 tl-app-01 2 Mon Jul 24 04:09:31 2023
192.168.10.10 00-B0-D0-63-C2-28 tl-pi-01 2 Mon Jul 24 10:52:48 2023