odhcpd relay mode is blocked by firewall by default
Username: Nikolay Amiantov
Origin: https://bugs.openwrt.org/index.php?do=details&task_id=389
odhcpd currently won’t work when put in
relay mode
if followed the manual naively. Turns out this is because firewall blocks incoming traffic to DHCPv6 server (port 547) from external DHCPv6 servers (port 547) from
WAN
zone by default. It may be a good idea to allow this out of the box, though I’m unsure if there are any security complications from this – I’m a newcomer to IPv6. Replies come with the source global IPv6 address of DHCPv6 server to the global IPv6 address of the router, so it’s difficult to make a more constrained rule without hardcoding them or at least the prefix.
Example rule which fixes relay mode:
config rule option enabled '1' option target 'ACCEPT' option src 'wan' option proto 'udp' option dest_port '547' option name 'Allow DHCPv6 Relay' option family 'ipv6' option src_port '547'
LEDE revision: 3e7b894a