Sorry, hit return to fast. Centos 7 joined to AD. After reboot, wbinfo reports domain as offline. Waiting some minutes or restarting winbind brings domain online. The unit-file for systemd has: After=network.target. According to https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/ network.target does not ensure fully working networking. Changing to After=network-online.target as recommended for clients resolved the problem. Cheers Heinrich
Not reproducible on RHEL samba-winbind-4.7.1-9.el7_5.x86_64