Re: IPv6 router is not forwarding packets
- Date: Mon, 07 Jan 2019 23:06:36 +0100
- From: Rainer Dorsch <ml@xxxxxxxxxxx>
- Subject: Re: IPv6 router is not forwarding packets
many thank again for your reply.
Am Sonntag, 6. Januar 2019, 21:40:21 CET schrieb Ulf Volmer:
> Yes, looks weird. I have no idea why this happens.
> Just one point, the response times of hop 3 in your second traceroute
> are quite low (instead of hop 2 in the first one). Are you sure that hop
> 3 isn't somewhere in your LAN?
Good observation. I mirrored the traffic to the ISP router (fritz.box) to
another unused switch port and used tcpdump to record it.
Looks unsuspicious to me. I see the traceroute packets outgoing (three per hop
limit as from home). The only difference is that the I get an "administratively
prohibited" type back (probably what traceroute marks with the X).
shows a screenshot of the first ICPMv6 packet which returns from the "wrong"
>From your observation on the timings, I would conclude that the packet does
not leave the IP router (fritz.box). The only surprising thing is that the
source ipv6 address is not the router address but some other address
To me it seems almost like an issue of the ISP router (fritz.box). The
fritzbox documentation contains a section
"Configure the IPv6 router so that it requests its own prefix from the FRITZ!Box
using IPv6 prefix delegation and that it announces its routing information to
the FRITZ!Box via router advertisement."
Which routing information does the fritzbox need? Do I need radvd for that?