ISC DHCPd with IPv6 “subnet_number():inet.c:53: Addr/mask length mismatch.”

If you’re getting an error along the lines of this in your syslog while trying to start a DHCPv6 server, you’ve probably got IPv4 ranges in your config file. It seems if it’s in IPv6 mode it can’t deal with IPv4 information being in the config file. :S

Mar  6 23:50:39 dnsbox dhcpd: Internet Systems Consortium DHCP Server 4.1-ESV-R4
Mar  6 23:50:39 dnsbox dhcpd: Copyright 2004-2011 Internet Systems Consortium.
Mar  6 23:50:39 dnsbox dhcpd: All rights reserved.
Mar  6 23:50:39 dnsbox dhcpd: For info, please visit https://www.isc.org/software/dhcp/
Mar  6 23:50:39 dnsbox dhcpd: subnet_number():inet.c:53: Addr/mask length mismatch.
Mar  6 23:50:39 dnsbox kernel: [3228221.642323] init: isc-dhcp-server6 pre-start process (26822) terminated with status 1
Mar  6 23:53:13 dnsbox dhcpd: Internet Systems Consortium DHCP Server 4.1-ESV-R4

So, rip the IPv4 information out of your /etc/dhcp/dhcpd6.conf file and you should be good to go.



#errors #fail #IPv6 #ISC DHCP #Ubuntu