Anyone having problems with dhcpd6?

[bimmerdriver]

I have two opnsense systems, both running on windows server 2012r2 hyper-v. One system is running the latest release and the other is running 19.1b. Yesterday, I updated both of them and now dhcpd6 is broken on both of them.

My ISP provides a /56 prefix. I also have two other *sense systems running on the same hyper-v server. Both are working properly, so I don't think this issue is related to my ISP.

Here is a message from the general log:

opnsense: /usr/local/etc/rc.newwanipv6: The command '/usr/local/sbin/dhcpd -6 -user dhcpd -group dhcpd -chroot /var/dhcpd -cf /etc/dhcpdv6.conf -pf /var/run/dhcpdv6.pid hn1' returned exit code '1', the output was 'Internet Systems Consortium DHCP Server 4.4.1 Copyright 2004-2018 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ /etc/dhcpdv6.conf line 15: network mask too short prefix6 2001:560:74b0:2800:: 2001:560:74b0:2800::/48; ^ Configuration file errors encountered -- exiting If you think you have received this message due to a bug rather than a configuration issue please read the section on submitting bugs on either our web page at www.isc.org or in the README file before submitting a bug. These pages explain the proper process and the information we find helpful for debugging. exiting.'

Note, the message is referring to /48. Not sure where that comes from.

[mrkev]

Hi,

My dhcpv6 seems to be working ok but then again I get a /48 from my ISP. Have you tried enabling debug under  the DHCPv6 client on the interface to see if that gives you anymore information?

[bimmerdriver]

Are you talking about the debug option for dhcp6c? I did enable it, but I didn't see any additional information. The problem is not on the WAN side anyway. It's on the LAN. It's getting a prefix and ipv6 is working properly, at least evidenced by being able ping an ipv6 host with the WAN as the source.

[bimmerdriver]

I searched the log again and found a few instances of this message:

opnsense: /interfaces.php: Warning! services_dhcpdv6_configure() found no suitable IPv6 address on hn1

[bimmerdriver]

This is sorted out, thanks marjohn56. I guess there was a change in the dhcpd6 default settings. It was trying to set up the LAN using a /48, which is not possible, considering there is only a /56 prefix from the ISP. Changed the prefix size to /64 with ::00 to ::FF as the range and now it's working. I've never had to touch those settings before when installing a "basic" configuration. (I like it better the old way, FWIW.)

[marjohn56]

I've fixed this and issued a PR for 19.1, not sure there will another 18.7 release so I have not back ported the fix.

[bimmerdriver]

@marjohn56 Thanks very much.