OPNsense Forum

Archive => 17.1 Legacy Series => Topic started by: rheller on July 14, 2017, 08:52:19 pm

Title: 17.1.9 and DHCP: Behaviour changed
Post by: rheller on July 14, 2017, 08:52:19 pm
Hi community

Yesterday I upgraded from my 2 month old Installation to the actual 17.1.9. All worked fine and therefore I went finally to bed having a quiet sleep.

But today there was not anymore Internet available at home (my wife gave me hell but fortunately I was at work  ;D )

This night, after checking my router as well asthe Firewall I finally discovered that DHCP was the cause. In my configuration I did not define the Default Gateways to be transmitted to the clients since if there is no GW defined, OPNsense uses the Interface Address as the GW for the clients. It seems that the actual version of the DHCP Server does not do that anymore. At least before explicitely defining the GW address I had no GW set on the Clients and, of course, after setting it all worked fine.

I would recommend for the next Version to either correct this 'to the old behaviour' or, as my favorite, change the (i) text on the DHCP Setup page to something like 'define the IP address of the GW, leave blank for no assignment'.

Regards, Ralph
Title: Re: 17.1.9 and DHCP: Behaviour changed
Post by: franco on July 16, 2017, 10:23:37 am
Hi Ralph,

I don't think anything has changed here. Sometimes a PPPoE modem may get a faulty DHCP lease and subsequently the DHCP server will not be able to forward a server address. Maybe that happened.

Only way to know is to reboot and see if it's still wrong or back to where it should be.

Title: 17.1.9 and DHCP: Behaviour changed
Post by: rheller on July 20, 2017, 05:09:23 pm
Hi Franco

Thanks for your response. Well, a reboot did not help really. After a reboot (of all that was possible) I still had the case that there was no GW address transmitted if there was no GW address given on the DHCP Service configuration.

By the way, my setup if the WWW connection has, if seen from the WWW itself, first the modem/router from the provider ('takes out' my phone to an analog connector, and having a private IP net ( and then comes the OPNsense box doing firewalling between its WAN side ( and three 'internal' LANs, for whose it is also providing DHCP leases.

Regards, Ralph