Router does not renew IPv6 routes after they expire

Hi there,

I've been using a fiber service with a dual-stack connection (IPv4 through PPPoE and IPv6 through DHCP) from my previous ISP without any issues. Recently, I switched to a new ISP that uses DOCSIS technology and provides a dual-stack connection through DHCP.

In my setup, the cable modem is in bridge mode, and my router (running OpenWrt) handles all the routing. It’s been a week since the switch, and I’ve noticed that my router and all devices connected to it lose their IPv6 connectivity after a certain period. There are no error messages in the system log, except for occasional warnings saying daemon.warn odhcpd[XXXX]: No default route present, overriding ra_lifetime!, which I believe means there's no IPv6 routes.

Whenever I reboot the router or restart the wan6 interface, the IPv6 connection returns but only for a short time before it drops again. After some troubleshooting, I discovered that the connection drops whenever the IPv6 routes expire, and the router does not seem to attempt to renew these routes.

Here are my WAN settings:

config interface 'wan'
	option device 'wan'
	option proto 'dhcp'
	option peerdns '0'
	list dns ''
	list dns ''

config interface 'wan6'
	option device 'wan'
	option proto 'dhcpv6'
	option reqaddress 'try'
	option reqprefix 'auto'
	option peerdns '0'
	list dns '2606:4700:4700::1111'
	list dns '2606:4700:4700::1001'

Any thoughts on why this might be happening and how to resolve this issue?

Anyone? I've tried a minimal OpenWrt build with default settings, but I'm still experiencing the same issue.

Same issue. I haven't found a solution yet.

Today I woke up with no service from my ISP for around 30 minutes. After they restored internet access, my router came back online automatically. Interestingly, the IPv6 upstream has been stable for the past six hours without any issues.

This makes no sense to me.