IPv6

Some notes about configuring IPv6 at BitFolk.

Your IPv6 assignment

By default customers are assigned a /64 of IPv6 space that starts with 2001:ba8:1f1:. The next four hexadecimal digits will identify your /64. For example:

$ ip -6 addr show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 2001:ba8:1f1:f004:a800:ff:fe6a:380c/64 scope global 
       valid_lft forever preferred_lft forever

This would indicate that 2001:ba8:1f1:f004::/64 is this customer's assignment.

In this case the address 2001:ba8:1f1:f004:a800:ff:fe6a:380c has been dynamically assigned, but all addresses between 2001:ba8:1f1:f004::2 and 2001:ba8:1f1:f004:ffff:ffff:ffff:ffff are available to the customer for assignment (2⁶⁴-2 addresses). 2001:ba8:1f1:f004::1 is used for the IPv6 default gateway.

Disabling autoconfiguration

You might wish to disable autoconfiguration and statically assign your IPv6 addresses. The typical way to do this is with the files in /proc/sys/ (or equivalent settings using sysctl). The following files in /proc/sys/ are relevant:

/proc/sys/net/ipv6/conf/default/accept_ra
/proc/sys/net/ipv6/conf/all/accept_ra
/proc/sys/net/ipv6/conf/eth0/accept_ra
/proc/sys/net/ipv6/conf/default/autoconf
/proc/sys/net/ipv6/conf/all/autoconf
/proc/sys/net/ipv6/conf/eth0/autoconf

If you echo "0" to all of the above files then IPv6 autoconfiguration will be disabled.

The best way to do this will vary by distribution.

Debian/Ubuntu

You could put something like this in /etc/network/interfaces:

iface eth0 inet6 static
    address 2001:ba8:1f1:f004::2
    netmask 64
    gateway 2001:ba8:1f1:f004::1
    post-up echo 0 > /proc/sys/net/ipv6/conf/default/accept_ra
    post-up echo 0 > /proc/sys/net/ipv6/conf/all/accept_ra
    post-up echo 0 > /proc/sys/net/ipv6/conf/$IFACE/accept_ra
    post-up echo 0 > /proc/sys/net/ipv6/conf/default/autoconf
    post-up echo 0 > /proc/sys/net/ipv6/conf/all/autoconf
    post-up echo 0 > /proc/sys/net/ipv6/conf/$IFACE/autoconf

$IFACE is replaced by the name of the interface by the network configuration scripts.