Update salt/files/ferm.conf

salt/files/ferm.conf

 @def $ownASN6 = (2a0f:3786::/40);
 @def $saltmaster = (2a01:4f8:192:11d2::99);
-@def $ownExternal6 = (2001:bc8:1864:40e::);
+@def $ownExternal6 = (2001:bc8:1864:40e::1);
 
 domain (ip6) {
   table filter {