Sophos Firewall: DHCP over IP Alias

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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.

  • 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]