Disclaimer: Please contact Sophos Professional Services if you require assistance with your specific environment and special thanks to Sanket Shah  for providing the Solution.

Overview

This Recommend Read shows you how to configure a DHCP server on an Alias IP

Alias IP

You may refer to the following KB for reference:

Add an alias

Step 1:Creating an Alias on Physical Interface

Go to Network> Interfaces, click Add interface and then select Alias.

Step 2:Alias IP Configurations

 Specify the following

• Physical Interface
• IP version
• IPv4/Netmask or IPv6/Prefix

DHCP for Alias IP

Go to Network > DHCP > Server > Add.
Create an Alias Network Range.
Notes:

• Interface: Alias Interface won't show on the Interface drop-down. Select the Port where Alias is created.
  • Ex. Port1
• Dynamic IP Lease: “ IP Alias” needs to be input manually.
• Gateway: “Use interface IP as gateway” needs to be unchecked
  • Enter IP address of Alias IP

See the screenshot below.

To further verify.
Go back to Network > DHCP > Servers.

Network > Interfaces

DHCP Leasing on a workstation

In command prompt

Type ipconfig /release and then Ipconfig /renew

Added release/renew for ipconfig
[edited by: Erick Jan at 12:07 AM (GMT -8) on 24 Jan 2023]