dch-gw: Add IPv6 ULA prefix to pyrocufflink.blue

For internal services, particularly DNS, it is easier to use a ULA
prefix than rely exclusively on routed addresses, since these can change
relatively frequently.

group_vars/dch-gw/dch-network.yml

@@ -18,9 +18,12 @@ dch_networks:
     description: pyrocufflink.blue AD domain members only
     vlan_id: 30
     ipv4_address: 172.30.0.0/26
+    ipv6_address: fd99:8cd7:6528:fe1e::/64
     router_iface: vlan30
     dns_search:
     - pyrocufflink.blue
+    dns_servers:
+    - fd99:8cd7:6528:fe1e::4:1
     dns_servers_v4:
     - 172.30.0.4
     sla_id: 30