Model : Archer C7 (AC 1750)

Hardware Version : v1

Firmware Version : 3.15.3 Build 150511 Rel.55816n

ISP : Telecolumbus (Berlin, Germany)


I use my Archer C7 behind a cable box of carrier Telecolumbus (box is CH7485E). This cable box is in bridge mode.

For IPv6 I use DHCPv6 with IPv6 prefix delegation. This works - but with a strange drawback.

I start my Archer C7 and my PC. The prefix delegation always works. But then nothing is reachable via IPv6 (I try to ping Google DNS 2001:4860:4860::8888 for example).

Then I check WAN and LAN setup in the router GUI and all looks fine. I check my PC (IP addresses and routing) and also this is OK.

This is really strange. Then I have two options: I can either reboot the cable box or I can release and renew the IPv6 delegation in the router GUI.

Both methods work. But of course I would prefer that this would be not necessary.

Does anybody have an idea what could cause such a behaviour and how this could be fixed?