OPNsense Forum

Archive => 20.1 Legacy Series => Topic started by: IsaacFL on May 26, 2020, 09:55:58 pm

Title: Is there a way to Edit DHCPv6 configuration
Post by: IsaacFL on May 26, 2020, 09:55:58 pm
I am trying to test a DHCPv6 configuration with the RA set to Stateless.

I would like to test if it is possible to get the DHCPv6 server to only provide "other" information such as DNS without assigning addresses. When I leave the address range empty, it bombs out.

Looking at /var/dhcpd/etc/dhcpdv6 I see (cleaned up):
Code: [Select]
option dhcp6.domain-search "xxx.xxxxxxx.com";

default-lease-time 7200;
max-lease-time 86400;
log-facility local7;
one-lease-per-client true;
deny duplicates;
ping-check true;
update-conflict-detection false;
authoritative;

subnet6 2605:e000:abcd:ef10::/64 {
  range6 2605:e000:abcd:ef10:::: 2605:e000:abcd:ef10::::;
  option dhcp6.name-servers 2605:e000:abcd:ef10:ca15:5dff:feff:2b00;

}

ddns-update-style none;

the line with the "range6" weirdness is not liked by the DHCP.

From reading Linux documentation, the correct configuration for Stateless is to completely delete the range6 line and it should work.  This is in Linux, who knows about FreeBSD. Hence the test.

When I edit the file manually it puts it back in and dies.

Title: Re: Is there a way to Edit DHCPv6 configuration
Post by: Maurice on May 26, 2020, 10:34:06 pm
I would like to test if it is possible to get the DHCPv6 server to only provide "other" information such as DNS without assigning addresses.

That should be possible. Support for this use case was added some time ago.

the line with the "range6" weirdness is not liked by the DHCP.

Indeed, that's phony.

From reading Linux documentation, the correct configuration for Stateless is to completely delete the range6 line and it should work.

That's 100% correct and this is how it should be here, too.

When I edit the file manually it puts it back in and dies.

Yeah, manual edits won't stick.

Is this a tracking interface? Franco added the option to leave the DHCPv6 range empty some time ago and I tested this back then. But it might be possible that it was only ever tested with static interfaces. I'll check.

Cheers

Maurice
Title: Re: Is there a way to Edit DHCPv6 configuration
Post by: Maurice on May 26, 2020, 11:09:34 pm
As suspected: Was broken for track interfaces. Fix:

opnsense-patch e20c705

Cheers

Maurice
Title: Re: Is there a way to Edit DHCPv6 configuration
Post by: IsaacFL on May 26, 2020, 11:27:43 pm
It was indeed a tracking interface.
Title: Re: Is there a way to Edit DHCPv6 configuration
Post by: IsaacFL on May 26, 2020, 11:29:03 pm
As suspected: Was broken for track interfaces. Fix:

opnsense-patch e20c705

Cheers

Maurice

I suspected it was a bug but wanted to try to test the fix prior to submitting an issue.