DHCP Server Issue

[zahid_salman]

I need to configure another pool on currently running DHCP Server on fortigate unit 1240B.

The already assigned IP Pool cannot be extended due to some technical reason.

Please suggest

[ede_pfau]

hi,

from the v5 CLI Reference:

You can only add one DHCP server to an interface.

This is for a good reason: if you had 2 or more DHCP servers on an interface they would compete to fulfill client's requests. You could not predict with confidence from which IP range a client would get it's address.

I recommend to enlarge the existing address space. Do so by expanding the subnet mask.

Example:

You have now: 192.168.16.[1-254] with mask 255.255.255.0

Enlarge the subnet mask to 255.255.240.0 to gain 15 more Class C subnets, i.e. 192.168.[16-31].[1-254]. That is 3.810 more addresses for your LAN.

[zahid_salman]

Thanks for the time and review.

Subnet extension was not possible b/c of default gateway. There are some other services on other /24 by which cannot change subnet mask which are statically assigned.

Another option on which I am focusing is that to create the new vlan for the LAN and assign /22 for it can be further use in future as per customer growth.