The error sequence indicates multiple failure points when trying to join an AD domain using realmd:

DNS update failed: NT_STATUS_INVALID_PARAMETER
[...]
realm: Couldn't join realm: Message did not receive a reply
[...]
Process /usr/lib/dbus-1.0/dbus-daemon-launch-helper received signal 11

Before troubleshooting, verify these base requirements:

# Verify installed packages
dpkg -l realmd sssd samba-common krb5-user sssd-tools

# Check service status
systemctl status realmd.service
systemctl status sssd.service

1. Configure Manual DNS Settings

Edit /etc/resolv.conf to point to your AD DNS servers:

nameserver 10.7.0.2
nameserver 10.7.0.3
search ad.example.com

Make it persistent by editing /etc/network/interfaces:

dns-nameservers 10.7.0.2 10.7.0.3
dns-search ad.example.com

2. Repair D-Bus Configuration

First try restarting the D-Bus service:

systemctl restart dbus

If errors persist, check for corrupted configurations:

# Reinstall D-Bus
apt-get install --reinstall dbus

# Verify policy files
ls -la /usr/share/dbus-1/system-services/org.freedesktop.realmd.service

3. Manual Domain Join Process

As a fallback, perform manual domain join steps:

# Configure krb5.conf
echo "[libdefaults]
    default_realm = AD.EXAMPLE.COM
    krb4_config = /etc/krb.conf
    krb4_realms = /etc/krb.realms
    kdc_timesync = 1
    ccache_type = 4
    forwardable = true
    proxiable = true" > /etc/krb5.conf

# Test Kerberos authentication
kinit Administrator@AD.EXAMPLE.COM

# Create sssd.conf manually
echo "[sssd]
config_file_version = 2
services = nss, pam
domains = ad.example.com

[domain/ad.example.com]
id_provider = ad
access_provider = ad
auth_provider = ad
chpass_provider = ad
ldap_schema = ad
ldap_id_mapping = True
cache_credentials = True
ldap_access_order = expire
ldap_account_expire_policy = ad
ldap_force_upper_case_realm = true" > /etc/sssd/sssd.conf

chmod 600 /etc/sssd/sssd.conf
systemctl restart sssd

After implementing the solution:

# Check domain membership
realm list

# Verify user lookup
getent passwd Administrator@ad.example.com

# Test authentication
su - Administrator@ad.example.com

If realmd continues to fail, use Samba's native tool:

# Install additional packages
apt-get install winbind libnss-winbind libpam-winbind

# Join domain manually
net ads join -U Administrator -S ad.example.com

# Configure Winbind
echo "[global]
    workgroup = AD-EXAMPLE
    security = ads
    realm = AD.EXAMPLE.COM
    idmap config * : backend = tdb
    idmap config * : range = 2000-9999
    idmap config AD-EXAMPLE : backend = rid
    idmap config AD-EXAMPLE : range = 10000-999999
    winbind use default domain = yes
    winbind enum users = yes
    winbind enum groups = yes" >> /etc/samba/smb.conf

systemctl restart winbind

---

When attempting to join an Active Directory domain using realmd on Ubuntu 14.04 LTS, you might encounter the following critical error:

realm: Couldn't join realm: Message did not receive a reply (timeout by message bus)
realm: Couldn't connect to realm service: Error calling StartServiceByName
Process received signal 11

The issue typically involves these components:

• realmd service (v0.3.0 or earlier)
• SSSD (System Security Services Daemon)
• Samba configuration
• Kerberos authentication

1. Verify Package Installation

First ensure all required packages are properly installed:

sudo apt-get update
sudo apt-get install realmd sssd sssd-tools samba-common krb5-user packagekit

2. Fix the D-Bus Crash

The "signal 11" error indicates a crash in the D-Bus subsystem. Apply this workaround:

sudo sed -i 's/^ExecStart=.*/ExecStart=\/usr\/sbin\/realmd --debug/' /usr/lib/systemd/system/realmd.service
sudo systemctl daemon-reload
sudo service realmd restart

3. Proper Domain Join Command

Use this enhanced join command with additional parameters:

sudo realm join --verbose --client-software=sssd ad.example.com -U Administrator \
--computer-ou="OU=Linux,DC=ad,DC=example,DC=com" \
--automatic-id-mapping=no \
--membership-software=samba

4. Manual SSSD Configuration

If automatic configuration fails, manually edit /etc/sssd/sssd.conf:

[sssd]
domains = ad.example.com
config_file_version = 2
services = nss, pam

[domain/ad.example.com]
ad_domain = ad.example.com
krb5_realm = AD.EXAMPLE.COM
realmd_tags = manages-system joined-with-samba 
cache_credentials = True
id_provider = ad
krb5_store_password_if_offline = True
default_shell = /bin/bash
ldap_id_mapping = True
use_fully_qualified_names = True
fallback_homedir = /home/%u
access_provider = ad

5. Verify Kerberos Configuration

Ensure /etc/krb5.conf contains:

[libdefaults]
default_realm = AD.EXAMPLE.COM
rdns = false
dns_lookup_kdc = true

[realms]
AD.EXAMPLE.COM = {
    kdc = ad.example.com
    admin_server = ad.example.com
}

[domain_realm]
.ad.example.com = AD.EXAMPLE.COM
ad.example.com = AD.EXAMPLE.COM

• Check logs: journalctl -u realmd and /var/log/sssd/*.log
• Verify time synchronization: sudo apt-get install ntp
• Test basic connectivity: host ad.example.com and ping ad.example.com
• Check DNS resolution: nslookup ad.example.com

If realmd continues to fail, consider manual Samba join:

sudo net ads join -U Administrator -S ad.example.com
sudo service samba restart
sudo service sssd restart