DHCP Relay dropping GW

Just curious, René - why must you use Relay?

Cheers - Bob

Hi Bob.

Normally I would relay traffic through a switch, but atm this is the easy work around.

I need to relay the traffic to get IP numbers for the different VLANS. The IP settings get sent to the differet VLANS, but the GW returned is blanked? So I get the settings, but loose the GW - so the IP address and info received doesn't work.

Cheerz mate,

René

HI René, 

As you are facing issue with the DHCP with the appliance used as a DHCP relay. The device would not block such request , instead it would be forwarded to the server and when a reply is received it would simply reply to the machine that would initiate the request ,  Could you test it with your DHCP server by using a test machine in the Same LAN/Vlan of the DHCP server . 

Configuration for DHCP Relay

The Network Services > DHCP > Relay tab allows you to configure a DHCP relay. The DHCP service is provided by a separate DHCP server and the UTM Appliance works as a relay. The DHCP relay can be used to forward DHCP requests and responses across network segments. You need to specify the DHCP server and a list of interfaces between which DHCP traffic shall be forwarded.

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To configure a DHCP relay, proceed as follows:

1. On the Relay tab, enable DHCP Relay.

You can either click the status icon or the Enable button.

The status icon turns amber and the DHCP Relay Configuration area becomes editable.

2. Select the DHCP server.

3. Select an interface.

DHCP requests arriving on these interfaces will be forwarded to the selected DHCP server.

4. Click Apply.

Your settings will be saved.

To cancel the configuration, click Abort Enable or the amber colored status icon.

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Taken from Article 115147  community.sophos.com/.../115147

If you got the proper results such as gateway information . Then you would need to Capture the packets as the initial set up on the DHCP server and the client end PC and message me both PCAPs and also mention the MAC address and the IP address to analyze the logs . So I would provide you a concrete resolution .

You may also log a Ticket for  the same if you wish and also message the ticket ID.

Thanks and Regards 

Aditya Patel | Network and Security Engineer.

Update...

Problem solved.

Seemed like one of the backend DHCP servers was sick, and for some reason didn't hand out the GW. DHCP reinstalled and reinstated on the server fixed the issue. So it works as basic as it looks - as long as the HA setup behind doesn't get ill.

Thanks to all for feedback. :o)

HI Rane, 

Thanks for an Update ,Glad it worked out for you.  If you have any Query / issue please keep up posted on Community for Sophos.

Thanks and Regards 

Aditya Patel | Network and Security Engineer,