Hello. First of all, excuse my English, I am French. I would like to create a trust relationship between my two DC Samba4 sc.local and rt.local. I was surprised to find no documentation on trust relationships. Using the help, I used the command: /usr/local/samba/bin/samba-tool domain trust create sc.local --type=external --direction=both --create-location=both -U Administrator at sc.local%password But it answers me: LocalDomain Netbios[RT] DNS[rt.local] SID[S-1-5-21-868514845-2905818245-770643559] RemoteDC Netbios[PDC] DNS[pdc.sc.local] ServerType[PDC,GC,LDAP,DS,KDC,TIMESERV,CLOSEST,WRITABLE,GOOD_TIMESERV,FULL_SECRET_DOMAIN_6] RemoteDomain Netbios[SC] DNS[sc.local] SID[S-1-5-21-1385687273-894974810-3564316924] smb_signing_good: BAD SIG: seq 1 ERROR: REMOTE_DC[pdc.sc.local]: failed to connect netlogon server - ERROR(0xC0000022) - Access denied What is this netlogon server?