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Bug #11149

open

DHCP relay won't start with DHCP server behind gateway

Added by Mark Lavrijsen 10 months ago. Updated 7 months ago.

Status:
New
Priority:
Normal
Assignee:
-
Category:
DHCP Relay
Target version:
-
Start date:
12/10/2020
Due date:
% Done:

0%

Estimated time:
Plus Target Version:
Release Notes:
Default
Affected Version:
2.5.0
Affected Architecture:
All

Description

This is the case current 2.5.0 development snapshot as of today.

Configuration:
em0 --> LAN2 --> DHCP relay should listen here
em1 --> LAN1 --> has default gateway, DHCP server is on another subnet behind gateway
(note, it may have something to do with the "gateway" in on "old" LAN interface?)

The error thrown is: /services_dhcp_relay.php: No suitable upstream interfaces found for running dhcrelay!
As if it's unable to determine that it must use em1 as the upstream interface. But that interface is the only active interface with a gateway.

This from the command line does work as expected:
/usr/local/sbin/dhcrelay –i em0 –iu em1 <ip of dhcp server>.

The relay then works.

When adding a third interface directly in the same network of the DHCP server, the relay then starts without issues and works from the GUI.

Actions #1

Updated by Mark Lavrijsen 10 months ago

And to be more compete, if I then disable that third interface, the DHCP relay then again won't start(same error).

Actions #2

Updated by John Cinuy 8 months ago

I have the same problem after an upgrade with our XG 7100 with 21.02-RELEASE-p1
The DHCP server is in another subnet and the DHCP relay doesn't want to start

Before upgrade, everything work fine but after upgrade, the service stay down unless i configure an IP adress in the same network of the DHCP server

Any solution for that problem ?

Actions #3

Updated by Viktor Gurov 8 months ago

  • Status changed from New to Duplicate

see #11523

Actions #4

Updated by Mark Lavrijsen 8 months ago

John Cinuy wrote:

I have the same problem after an upgrade with our XG 7100 with 21.02-RELEASE-p1
The DHCP server is in another subnet and the DHCP relay doesn't want to start

Before upgrade, everything work fine but after upgrade, the service stay down unless i configure an IP adress in the same network of the DHCP server

Any solution for that problem ?

Well, I have found two possible workarounds:
1) use the above command to start the relay.
2) Fiddle with outbound NAT rules. In my case, dhcrelay starts after disabling automatic outbound NAT.

Actions #5

Updated by Mark Lavrijsen 7 months ago

It seems that the "bug" has indeed something to do with Outgoing NAT & dhcrelay. When starting from commandline dhcrelay it doesn't care, but "automatically" from pfSense something goes wrong.

Actions #6

Updated by Viktor Gurov 7 months ago

  • Status changed from Duplicate to New

seems another issue
related to #9466 and #10416

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