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IPv6 Gateway Unreachable

30-08-2013, 00:18
Oh gods, I cannot believe I didn't try that. Must have been the tiredness taking over.

That sorted it out instantly. Thanks for the quick reply and the solution, very much appreciated.


30-08-2013, 00:01
You need to add the route in two steps. First tell where the gateway can be found (as it falls outside your /64 range) and then add the default route. Like so:

iface eth0 inet6 static
	address 2001:41d0:2:183d::1
	netmask 64
	post-up /sbin/ip -f inet6 route add 2001:41d0:2:18ff:ff:ff:ff:ff dev eth0
	post-up /sbin/ip -f inet6 route add default via 2001:41d0:2:18ff:ff:ff:ff:ff
	pre-down /sbin/ip -f inet6 route del default via 2001:41d0:2:18ff:ff:ff:ff:ff
	pre-down /sbin/ip -f inet6 route del 2001:41d0:2:18ff:ff:ff:ff:ff dev eth0

29-08-2013, 23:52
Hi all,

Hoping you can give a hand, this problem is totally stumping me.

I have started to more actively use IPv6 and noticed this evening that my server wasn't able to ping anything in the IPv6 address space other than itself.

I did some digging in the forums and came up with a few solutions - checking autoconf, making sure there was a route to the gateway etc.

During this I noticed that indeed, there was no default route to my gateway, however all attempts to add one have been dead ends.

I have tried:
  • Inserting the route with ip -6 route add
  • Inserting the route with route -A
  • Editing /etc/network/interfaces with the gateway

All of these return
# ip -6 route add default via 2001:41d0:2:18ff:ff:ff:ff:ff dev eth0
RTNETLINK answers: No route to host
SIOCADDRT: No route to host
my interfaces file is as follows:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo eth0
iface lo inet loopback

allow-hotplug eth0
iface eth0 inet static

iface eth0 inet6 static
        pre-up modprobe ipv6
        address 2001:41d0:2:183d::1
        netmask 64
Would appreciate any help on this!