Fortigate firewall- DHCP lease time settings

1. Click on CLI console to login to Fortigate firewall

2. MYFORTIGATE # config system dhcp server

3. MYFORTIGATE (server) # show
config system dhcp server
edit 1
set auto-configuration disable
set default-gateway 172.16.20.99
set domain "ARMORIQUE"
set interface "internal"
config ip-range
edit 1
set end-ip 172.16.20.15
set start-ip 172.16.20.11
next
end
set lease-time 86400
set netmask 255.255.0.0
set dns-server1 172.16.20.99
next
end

4. MYFORTIGATE (server) # edit 1
 
5. MYFORTIGATE (1) # set lease-time <integer>
                  ( 300 ~ 8640000 seconds (5 minutes ~ 100 days)
                    0 for unlimited lease time )

Fortigate firewall- How to clear DHCP lease manually

1. Log in to Fortigate unit using browser.
2. 

 
3. Click on CLI Console to login to Firewall.
4.  For IPv4: type,
                   execute dhcp lease-clear  <ip address>
For IPv6:type,
                    execute dhcp6 lease-clear <ip address>

To clear all,
                   execute dhcp lease-clear all

Computer Help Notes link.........

http://www.itnotes.eu/