----
# /etc/network/interfaces
(...)
+# Dual stack:
+iface vmbr0 inet static
+ address 1.2.3.4
+ netmask 255.255.255.128
+ gateway 1.2.3.5
iface vmbr0 inet6 static
address fc00::31
netmask 16
gateway fc00::1
accept_ra 0
pre-up echo 0 > /proc/sys/net/ipv6/conf/$IFACE/disable_ipv6
+
+# With IPv6-only 'pre-up' is too early and 'up' is too late.
+# Work around this by creating the bridge manually
+iface vmbr1 inet manual
+ pre-up ip link add $IFACE type bridge
+ up echo 0 > /proc/sys/net/ipv6/conf/$IFACE/disable_ipv6
+iface vmbr1 inet6 static
+ address fc00:b:3::1
+ netmask 96
+ bridge_ports none
+ bridge_stp off
+ bridge_fd 0
+ bridge_vlan_aware yes
+ accept_ra 0
(...)
----