DHCP Firewall Windows

Windows_Firewall_DHCP.md

Adding a DHCP Firewall Rule

Note: This firewall rule will restrict your computer to only conduct DHCP exchange with a designated IP. If you move to another network and rely on DHCP, you will need to remove this rule for your DHCP to work properly

1. Open the Windows Security Center:

   • Press the Windows key + I to open the Settings app.
   • Navigate to "Privacy & Security" and then select "Windows Security".

2. Access the Firewall & network protection settings:

   • In the Windows Security window, click on "Firewall & network protection".
   • Under the "Firewall & network protection" section, click on "Domain network".

3. Create a new outbound rule for the DHCP server:

   • In the "Domain network" settings, scroll down to the "Outbound rules" section.
   • Click on "Add a new rule".
   • In the "New Outbound Rule Wizard", select "Custom" and click "Next".
   • Select "UDP" as the protocol type and enter the port number for your local DHCP server (usually port 67).
   • In the "Remote IP address" section, select "These IP addresses" and enter the IP address of your local gateway.
   • Choose "Allow the connection" and click "Next".
   • Name the rule (e.g., "Allow DHCP from local gateway") and click "Finish".

4. Create a new inbound rule for the DHCP client:

   • Repeat the previous steps, but this time, select "Inbound rule" instead of "Outbound rule".
   • For the inbound rule, select "UDP" as the protocol type and enter the port number for your local DHCP client (usually port 68).
   • In the "Remote IP address" section, select "These IP addresses" and enter the IP address of your local gateway (e.g. 192.168.1.1).

5. Disable all other DHCP-related firewall rules:

   • In the "Firewall & network protection" section, click on "Advanced settings".
   • In the "Windows Defender Firewall with Advanced Security" window, navigate to "Inbound Rules" and "Outbound Rules".
   • Locate and disable any other DHCP-related rules that may be present.