DHCPv6-replay Mode not forwarding RA from WAN to LAN

[wenchiangh]

version:
name -a
Linux OpenWrt 6.12.43 #0 SMP Thu Aug 28 11:35:07 2025 aarch64 GNU/Linux

apk list | grep odhcpd
odhcpd-2024.05.08a298823-r1 aarch64_cortex-a53 {feeds/base/package/network/services/odhcpd} (GPL-2.0)
odhcpd-ipv6only-2024.05.08a298823-r1 aarch64_cortex-a53 {feeds/base/package/network/services/odhcpd} (GPL-2.0)
odhcpd-ipv6only-2024.05.08~a2988231-r1 aarch64_cortex-a53 {feeds/base/network/services/odhcpd} (GPL-2.0) [installed]

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setting up OpenWrt use DHCPv6-relay mode, and when service odhcpd restart, device in openwrt lan can use ipv6, but hours late device(such as macOS which use OpenWrt AP) will lost default route gateway of ipv6.

1. listen eth2 which upper router of openwrt, got RA in time

tcpdump -i eth2 -n -v icmp6 and 'icmp6[0]==134'

# many ra message one by one

2. listen device of br-lan, doesn't get an RA message

tcpdump -i br-lan -n -v icmp6 and 'icmp6[0]==134'

# no ra message

3. and then restate odhcpd service, step 2 which listen br-lan got ra message one by one, and macOS now can use ipv6

[Alphix]

@wenchiangh Are you not getting a prefix delegation from your ISP?

[systemcrash]

@wenchiangh please run latest master - there may have been changes which affect this scenario.

[Alphix]

And provide the contents of /etc/config/dhcp if it's still not working