IPv6 stops working after several minutes

Found solution (add accept_ra 1 in interfaces file):

After some Googling and finding an old Ubuntu bug, the puzzle got more clearer: The DHCP client in Debian 7 declines router advertisements by default. Do’h! A simple fix is to force your interface to accept router advertisements.

It’s quite logical but still a bug. Normally for IPv6 you will use autoconfig as DHCP replacement but at my office we want to monitor and check which client get’s which IP. So, we have DHCP running with IPv6 support.

So if you ever run in to this issue, make sure that your network configuration looks like this:

auto eth0
allow-hotplug eth0
iface eth0 inet dhcp
iface eth0 inet6 dhcp
accept_ra 1
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Problem:
Hi,

I'm testing with IPv6. My pc gets an ipv6 address from dhcpv6, i can ping6 ipv6.google.com. After several minutes ping6 stops working with message "ping: sendmsg: Network is unreachable". When I reboot the station it works for several minutes and then stops again. Anyone seen this behaviour and knows how to solve this?

I use 3.18.0-kali3-amd64

Regards,

Marc

I found the problem now I have to search for the solution:

Problem: if I observe the route on ipv6 I see, default via de80::c671... etc dev eth0 proto ra metric 1024 expires 1407 sec
The expires counts down to 0 then It increments by 10 start count down and when hitting -1 the default route disappears in the route table.
I use the command ip -6 route.

We use DHCP for distributing ipv6 addresses.

How can I solve this problem?

Regards Marc