DHCP server stops responding when interface goes down and up

mastermindpro · Apr 30, 2008, 2:54 PM

I have a client with a pfSense device that uses it for a full-time VPN tunnel to his corporate network from home. At home, he only has his laptop plugged directly into the LAN interface of the pfSense box (Alix hardware). When the laptop goes to sleep or he powers it down, the DHCP server stops responding on the LAN interface. I have to restart the DHCP service while the interface is in an up status and then have him manually repair the connection on his laptop.

Is there any way to keep the DHCP server responding on the LAN interface through a down-up cycle?

Perry · Apr 30, 2008, 3:04 PM

I would put a switch between them

mastermindpro · Apr 30, 2008, 3:12 PM

I know that would work, but it doesn't seem like this should be a problem in the first place.

hoba · Apr 30, 2008, 4:26 PM

I have the same setup at home for my neighbour. He is connected to an opt-interface with a crossovercable directly (seperate subnet firewalled against my lan with seperate dhcp server). I don't see this issue. Is the port bridged to anything or is another port bridged to this port? What do you see in the systemlogs regarding this problem?

mastermindpro · Apr 30, 2008, 4:30 PM

This is a log excerpt of all the time since the interface last went down and back up:

Apr 30 08:34:28 kernel: vr0: link state changed to DOWN
Apr 30 08:35:36 kernel: vr0: link state changed to UP
Apr 30 08:35:38 check_reload_status: rc.linkup starting
Apr 30 08:35:40 php: : Processing vr0 - start
Apr 30 08:35:40 php: : Hotplug event detected for vr0 but ignoring since interface is not set for DHCP
Apr 30 08:35:40 php: : Processing start -
Apr 30 08:35:40 php: : Not a valid interface action ""
Apr 30 08:35:40 php: : Processing -
Apr 30 08:35:40 php: : Not a valid interface action ""
Apr 30 08:36:27 dhcpd: Internet Systems Consortium DHCP Server V3.0.5
Apr 30 08:36:27 dhcpd: Copyright 2004-2006 Internet Systems Consortium.
Apr 30 08:36:27 dhcpd: All rights reserved.
Apr 30 08:36:27 dhcpd: For info, please visit http://www.isc.org/sw/dhcp/

I manually restarted the DHCP server at 8:36. The LAN (vr0) interface is not bridged with anything. I do have an enabled Opt1 that DHCP also listens on, but it's connected to a home router device…so it doesn't go down and up regularly. I'm not seeing any relevant information in the logs that would indicate why it's not working.

hoba · Apr 30, 2008, 4:49 PM

When the client is not able to receive a lease from the dhcp server do you see anything in the dhcp tab of the systemlogs? does status>services show the dhcp server still running?

mastermindpro · Apr 30, 2008, 4:57 PM

I don't see any errors in the DHCP logs…in fact, nothing appears during the time the client is trying to get a lease. The service claims to be running on the status page, but simply doesn't hand out leases unless it is restarted while the interface is up.

hoba · Apr 30, 2008, 5:03 PM

I assume we are talking about 1.2 release and not some beta or rc or even 1.0.1 version?

mastermindpro · Apr 30, 2008, 5:04 PM

You are correct…1.2 Embedded.

Perry · Apr 30, 2008, 5:06 PM

Did you confirm that you are using a crossovercable?

mastermindpro · Apr 30, 2008, 5:08 PM

I'm using a patch, but the laptop auto-MDI-X's it. Bear in mind it does work and pass data if I restart the DHCP server after the interface comes back up and force the laptop to renew it's lease.

hoba · Apr 30, 2008, 6:27 PM

Try to add an afterfilterchangesshellcommand-tag (see http://blog.pfsense.org/?p=31) to automatically restart the dhcp server on interface linkup. You'll have to download the config.xml and manually add a section to it and reupload it again.