Bacula IPv6 NIC Configuration
To be on a backup network a server will need to have a dedicated backup NIC. If up and configured correctly, the NIC should have an IPv6 address.
The NIC configuration for CentOS in /etc/sysconfig/network-scripts/ifcfg-eth1 (replace eth1 with backup NIC, this is em2 in CentOS 7) should be:
DEVICE=ETH1 HWADDR=[mac code] ONBOOT=yes IPV6INIT=yes IPV6_AUTOCONF=yes
Ubuntu in /etc/network/interfaces:
iface eth1 inet6 auto
Bring the devices up and down with ifdown and ifup as normal.
If the device picks up a local IPv6 address but not a global, it may be that ip6tables is running and blocking the dhcp ports.
Windows - just ensure that it has the TCP/IP6 protocol installed on the network adapter, and it's set to pick up an address automatically.