[Samba] DC2: TKEY is unacceptable, Failed DNS update?

[Jo L]

I installed
two virtual machines with Samba as domain controllers for the same domain. I
was struggling with network and DNS configuration initially, maybe my problem
is related. 

DC1 starts
up ok, the last line of the log reads

STATUS=daemon
'samba' finished starting up and ready to serve connections

DC2 starts
with plenty of lines 

 [2016/05/15 22:00:32.744910,  0]
../lib/util/util_runcmd.c:328(samba_runcmd_io_handler)

  /usr/sbin/samba_dnsupdate:
dns_tkey_negotiategss: TKEY is unacceptable

and also

[2016/05/15
22:00:34.232460,  0]
../source4/dsdb/dns/dns_update.c:294(dnsupdate_nameupdate_done)

  ../source4/dsdb/dns/dns_update.c:294: Failed
DNS update - NT_STATUS_UNSUCCESSFULBoth use bridge network configuration, static IP addresses, /etc/resolv.conf points to themselves (and the other), they can ping each other, but DC1 cannot resolve the name of DC2. I was assuming that the name information is part of the replicated information?When DC2 joined
DC1, resolv.conf was pointing to DC1. I changed that later on as I want to be
able to continue to operate DC2 while DC1 is down. Ultimately I want to run the
DCs in two different networks that may occasionally become disconnected.

What am I doing
wrong? 

Thx -
Joachim