With NetworkManager on 15.2 I get a fully functional IPv6 setup, with wicked on
the same machine it does not work. The machine is a workstation in the SUSE
Nuernberg office.

# ip -6 r
::1 dev lo proto kernel metric 256 pref medium
fe80::/64 dev br0 proto kernel metric 256 pref medium

# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group
default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: em1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0
state UP group default qlen 1000
    link/ether 54:bf:64:a4:23:15 brd ff:ff:ff:ff:ff:ff
4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group
default qlen 1000
    link/ether 54:bf:64:a4:23:15 brd ff:ff:ff:ff:ff:ff
    inet 10.160.4.65/16 brd 10.160.255.255 scope global br0
       valid_lft forever preferred_lft forever
    inet6 fe80::56bf:64ff:fea4:2315/64 scope link 
       valid_lft forever preferred_lft forever