Samba winbind: how to authenticate from trusted AD domain (one-way trust)?

Hello linux newbie here. **What I am trying to achieve:** to be able to login to Linux machine with Active Directory credentials from trusted domain. I have the following setup: +----------------+ +---------------+ +-----------+ | Forest B | | Forest A | | User in | | | one-way trust | | | domain B +----------+ Domain B +<--------------+ Domain A | | | | b.net | | a.net | +-----------+ | | | | | | | | +----------------+ +-------+-------+ | | | | | +-------+-------+ | | | Ubuntu 16.04 | | samba 4.7.12 | | | | | | | +---------------+ I have successfully joined my Ubuntu 16.04 to Active Directory domain A with samba winbind, but I am unable to login to the machine with user account that exists in domain B. Domain A and domain B are Active Directory domains and they have one-way trust so that domain A trusts domain B, but domain B does not trust domain A. Here are my smb.conf, krb5.conf and nsswitch.conf /etc/samba/smb.conf [global] workgroup = A security = ADS realm = A.NET encrypt passwords = yes idmap config *:range = 16777216-33554431 allow trusted domains = yes winbind trusted domains only = no kerberos method = secrets and keytab winbind refresh tickets = yes template shell = /bin/bash server string = %h server (Samba, Ubuntu) dns proxy = no log file = /var/log/samba/log.%m max log size = 1000 syslog = 0 panic action = /usr/share/samba/panic-action %d server role = standalone server passdb backend = tdbsam obey pam restrictions = yes unix password sync = yes passwd program = /usr/bin/passwd %u passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* . pam password change = yes map to guest = bad user usershare allow guests = yes [printers] comment = All Printers browseable = no path = /var/spool/samba printable = yes guest ok = no read only = yes create mask = 0700 [print$] comment = Printer Drivers path = /var/lib/samba/printers browseable = yes read only = yes guest ok = no /etc/krb5.conf [libdefaults] default_realm = A.NET dns_lookup_kdc = false krb4_config = /etc/krb.conf krb4_realms = /etc/krb.realms kdc_timesync = 1 ccache_type = 4 forwardable = true proxiable = true v4_instance_resolve = false v4_name_convert = { host = { rcmd = host ftp = ftp } plain = { something = something-else } } fcc-mit-ticketflags = true [realms] ATHENA.MIT.EDU = { kdc = kerberos.mit.edu:88 kdc = kerberos-1.mit.edu:88 kdc = kerberos-2.mit.edu:88 admin_server = kerberos.mit.edu default_domain = mit.edu } MEDIA-LAB.MIT.EDU = { kdc = kerberos.media.mit.edu admin_server = kerberos.media.mit.edu } ZONE.MIT.EDU = { kdc = casio.mit.edu kdc = seiko.mit.edu admin_server = casio.mit.edu } MOOF.MIT.EDU = { kdc = three-headed-dogcow.mit.edu:88 kdc = three-headed-dogcow-1.mit.edu:88 admin_server = three-headed-dogcow.mit.edu } CSAIL.MIT.EDU = { kdc = kerberos-1.csail.mit.edu kdc = kerberos-2.csail.mit.edu admin_server = kerberos.csail.mit.edu default_domain = csail.mit.edu krb524_server = krb524.csail.mit.edu } IHTFP.ORG = { kdc = kerberos.ihtfp.org admin_server = kerberos.ihtfp.org } GNU.ORG = { kdc = kerberos.gnu.org kdc = kerberos-2.gnu.org kdc = kerberos-3.gnu.org admin_server = kerberos.gnu.org } 1TS.ORG = { kdc = kerberos.1ts.org admin_server = kerberos.1ts.org } GRATUITOUS.ORG = { kdc = kerberos.gratuitous.org admin_server = kerberos.gratuitous.org } DOOMCOM.ORG = { kdc = kerberos.doomcom.org admin_server = kerberos.doomcom.org } ANDREW.CMU.EDU = { kdc = kerberos.andrew.cmu.edu kdc = kerberos2.andrew.cmu.edu kdc = kerberos3.andrew.cmu.edu admin_server = kerberos.andrew.cmu.edu default_domain = andrew.cmu.edu } CS.CMU.EDU = { kdc = kerberos.cs.cmu.edu kdc = kerberos-2.srv.cs.cmu.edu admin_server = kerberos.cs.cmu.edu } DEMENTIA.ORG = { kdc = kerberos.dementix.org kdc = kerberos2.dementix.org admin_server = kerberos.dementix.org } stanford.edu = { kdc = krb5auth1.stanford.edu kdc = krb5auth2.stanford.edu kdc = krb5auth3.stanford.edu master_kdc = krb5auth1.stanford.edu admin_server = krb5-admin.stanford.edu default_domain = stanford.edu } UTORONTO.CA = { kdc = kerberos1.utoronto.ca kdc = kerberos2.utoronto.ca kdc = kerberos3.utoronto.ca admin_server = kerberos1.utoronto.ca default_domain = utoronto.ca } A.NET = { admin_server = dc.a.net kdc = dc.a.net } B.NET = { admin_server = dc.b.net kdc = dc.b.net } [domain_realm] .mit.edu = ATHENA.MIT.EDU mit.edu = ATHENA.MIT.EDU .media.mit.edu = MEDIA-LAB.MIT.EDU media.mit.edu = MEDIA-LAB.MIT.EDU .csail.mit.edu = CSAIL.MIT.EDU csail.mit.edu = CSAIL.MIT.EDU .whoi.edu = ATHENA.MIT.EDU whoi.edu = ATHENA.MIT.EDU .stanford.edu = stanford.edu .slac.stanford.edu = SLAC.STANFORD.EDU .toronto.edu = UTORONTO.CA .utoronto.ca = UTORONTO.CA a.net = A.NET .a.net = A.NET b.net = B.NET .b.net = .B.NET [login] krb4_convert = true krb4_get_tickets = false /etc/nsswitch.conf passwd: compat winbind group: compat winbind shadow: compat gshadow: files hosts: files dns networks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis Most of the modification are based on these instructions, though I added the domain b to krb5.conf: https://docs.citrix.com/en-us/linux-virtual-delivery-agent/7-15-ltsr/installation-overview/ubuntu.html I have tried the following wbinfo commands: **wbinfo --online-status** shows domain A online, but domain B offline. **wbinfo -n B\\administrator** returns a SID and wbinfo -s SID returns the name **wbinfo -m** BUILTIN MYLINUX A B **wbinfo -K B\\user%password** returns the following error message: wbcLogonUser(B\user): error code was NT_STATUS_NO_LOGON_SERVERS (0xc000005e) error message was: No logon servers are currently available to service the logon request. Could not authenticate user [B\user%password] with Kerberos (ccache: FILE) I would really appreciate if someone could help me to solve this. How would I start to troubleshoot this issue?