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Ubuntu 12.04 Samba 4 – Active Directory Domain Controller |
With the recent stable release of Samba 4, it is possible to create a compatible Active Directory Domain Controller that runs on the Linux platform.
Setup
The following is how to setup and configure a basic Samba 4 domain controller running on Ubuntu 12.04. Once configured and installed, you can then administer Active Directory using Microsoft’s Remote Server Administration Tools from a Windows XP, Vista, or 7 client that supports Active Directory. Note: your Windows client must be a Professional, Business or Ultimate edition.
ü functioning basic server running Ubuntu x86_64 with root access
ü your Ubuntu server is using an IP address of 192.254.77.146 (change to your liking)
ü FQDN of ‘adhd.ssno.org‘ (change to your liking)
ü default gateway IP address: 192.254.77.129 (change to your network gateway)
ü a Windows XP, Vista or 7 client that supports Active Directory
ü DNS forwarding IP address using OpenDNS: 8.8.8.8 (change to you liking)
Download and Installation
1. Configure a fixed IP for your new server.
Edit /etc/network/interfaces and change the config to set a static IP. Please use your own IP information where applicable:
sudo nano /etc/network/interfaces
auto eth0 lo
iface lo inet loopback
iface eth0 inet static
address 192.254.77.146
netmask 255.255.255.224
broadcast 192.254.77.159
network 192.254.77.128
gateway 192.254.77.129
dns-nameservers 192.254.77.146
dns-search ssno.org
2. Login as root and update your server
# apt-get update
# apt-get upgrade
3. Install the following packages required for installing and building Samba 4:
# apt-get install glibc glibc-devel gcc python krb5-workstation krb5-libs pam_krb5
#apt-get install libacl-devel e2fsprogs-devel gnutls-devel readline-devel python-devel gdb pkgconfig
4. If there are any older samba packages remove them with apt-get:
# apt-get remove samba-winbind-client samba-common samba-client
5. Install git to dowload the latest Samba 4 version:
# apt-get install git-core
6. Use a directory of your choice and download the latest version of samba from git:
#cd /usr/src/
# git clone git://git.samba.org/samba.git samba-master
Configure and install Samba 4
#cd /usr/src/samba-master
#./configure
#make
#make install
After the install we will add the path to the bin and sbin directory of Samba:
#nano ~/.bashrc
add the following line at the bottom
export PATH=”/usr/local/samba/sbin:/usr/local/samba/bin:$PATH”
7. Reboot the server as a precaution so that all packages or kernel updates will be applied:
# shutdown -r now
Now we need to Provision Samba 4
The provision step sets up a basic user database, and is used when you are setting up your Samba4 server in its own domain.
As root issue this command:
# /usr/local/samba/bin/samba-tool domain provision
The ‘domain provision’ tool should pick defaults for you automatically. Change to your configurations if necessary:
Realm [SSNO.ORG]: Domain [MYDOMAIN]: (press Enter)
Server Role (dc, member, standalone) [dc]: (press Enter)
DNS backend (SAMBA_INTERNAL, BIND9_FLATFILE, BIND9_DLZ, NONE) [SAMBA_INTERNAL]: (press Enter)
DNS forwarder IP address (write 'none' to disable forwarding) [192.168.0.1]: 208.67.222.222
Administrator password: <your_secret_admin_password>
Retype password:
If above was successful, stdout should look similar to this:
Creating CN=MicrosoftDNS,CN=System,DC=mydomain,DC=com
Creating DomainDnsZones and ForestDnsZones partitions
Populating DomainDnsZones and ForestDnsZones partitions
Setting up sam.ldb rootDSE marking as synchronized
Fixing provision GUIDs
A Kerberos configuration suitable for Samba 4 has been generated at /usr/local/samba/private/krb5.conf
Once the above files are installed, your Samba4 server will be ready to use
Server Role: active directory domain controller
Hostname: samba
NetBIOS Domain: MYDOMAIN
DNS Domain: SSNO.ORG
DOMAIN SID: S-1-5-xx-xxxxxxxxxx-xxxxxxxxx-xxxxxxxxxx
NOTE: You may need to remove the ‘/usr/local/samba/etc/smb.conf’ file if you are re-running the provision command. If you encounter any errors when running the provision command, you may need to install the necessary missing packages or fix errors and then run ‘./configure’, ‘make’ and ‘make install’ commands again as stated above. Remember to do a ‘make clean’ in the root of your ‘samba-master’ directory before running ‘make’ again.
If the provision setup was successful reboot the server:
# shutdown -r now
Start Samba 4 AD DC
Start the samba daemon:
# /usr/local/samba/sbin/samba
If you would like Samba to start at boot, append the following to your ‘/etc/rc.d/rc.local’ file:
/usr/local/samba/sbin/samba
Testing Samba as an Active Directory DC
Verify you are indeed running the correct version of Samba. Your version should start with version 4 (note: samba daemon must be running):
# /usr/local/samba/sbin/samba -V
Version 4.1.0pre1-GIT-c1fb37d
Verify you are running the correct samba-client version:
# /usr/local/samba/bin/smbclient --version
Version 4.1.0pre1-GIT-c1fb37d
Now run this command to list the shares on your Samba4 server:
# /usr/local/samba/bin/smbclient -L localhost -U%
Domain=[MYDOMAIN] OS=[Unix] Server=[Samba 4.1.0pre1-GIT-c1fb37d]
Sharename Type Comment
--------- ---- -------
netlogon Disk
sysvol Disk
IPC$ IPC IPC Service (Samba 4.1.0pre1-GIT-c1fb37d)
Domain=[MYDOMAIN] OS=[Unix] Server=[Samba 4.1.0pre1-GIT-c1fb37d]
Server Comment
--------- -------
Workgroup Master
--------- -------
Configure DNS
You will need to edit your ‘/etc/resolv.conf’ and ‘/etc/sysconfig/network-scripts/ifcfg-eth0’ file so that Samba will use it’s internal DNS correctly. If you specified a forwarding DNS server when you provisioned earlier, DNS should work correctly (you can verify this in /usr/local/samba/etc/smb.conf). Here is an example of my current ‘/usr/local/samba/etc/smb.conf’ file:
# cat /usr/local/samba/etc/smb.conf
# Global parameters
[global]
workgroup = MYDOMAIN
realm = SSNO.ORG
netbios name = SAMBA
server role = active directory domain controller
dns forwarder = 8.8.8.8
[netlogon]
path = /usr/local/samba/var/locks/sysvol/ssno.org/scripts
read only = No
[sysvol]
path = /usr/local/samba/var/locks/sysvol
read only = No
Edit your ‘/etc/resolv.conf’ file to look like this:
# Generated by NetworkManager
domain ssno.org
nameserver 192.254.77.146
search ssno.org
Testing DNS
Make sure that samba is running and then test to make sure that DNS is working properly. Run the following commands and compare the output to what is shown:
# host -t SRV _ldap._tcp.ssno.org.
_ldap._tcp.ssno.org has SRV record 0 100 389 adhd.ssno.org.
# host -t SRV _kerberos._udp.ssno.org.
_kerberos._udp.ssno.org has SRV record 0 100 88 adhd.ssno.org.
# host -t A adhd.ssno.org.
adhd.ssno.org has address 192.254.77.146
The answers you get should be similar to the ones above (adjusted for your DNS domain name and hostname). If you get any errors, carefully check your system logs and your ‘/etc/resolv.conf’ and ‘/etc/network/interfaces’ files.
Disable Firewall (Optional)
To reduce the chances of problems you can completely disable the firewall on the Samba 4 server. Once you have successfully joined a Windows client to the domain you could then re-enable the firewall and configure IP Tables correctly.
Disable the firewall and then reboot the server.
Configure Kerberos
In Ubuntu, kerberos is handled by the ‘/etc/krb5.conf’ file. Make a backup copy of this original file, and then replace the existing file, if any, with the sample from /usr/local/samba/share/setup/krb5.conf.
# cp /usr/local/samba/share/setup/krb5.conf /etc/krb5.conf
Edit the file and replace ${REALM} with the value you chose for the ‘–realm’ parameter of the provision command earlier, make sure to enter the realm in uppercase letters. It should look something like this:
# cat /etc/krb5.conf
[libdefaults]
default_realm = SSNO.ORG
dns_lookup_realm = false
dns_lookup_kdc = true
Testing Kerberos
The simplest test is to use the ‘kinit’ command as follows:
# kinit administrator@SSNO.ORG
Password for administrator@SSNO.ORG:
Warning: Your password will expire in 41 days on Sun Feb 3 14:21:51 2013
NOTE: You must specify your domain realm SSNO.ORG in uppercase letters!!
‘kinit’ will not give you any output. To verify that Kerberos is working, and that you received a ticket, run the following:
# klist
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: administrator@SSNO.ORG
Valid starting Expires Service principal
12/23/12 15:39:28 12/24/12 01:39:28 krbtgt/SSNO.ORG@SSNO.ORG
renew until 12/24/12 15:39:19
NTP (Network Time Protocol)
Make sure that ‘ntpd’ is running and installed. If ‘ntp’ is not installed you can install it with APT-GET:
# apt-get install ntp
Enable ntpd:
# /etc/init.d/ntp start
Also, use the ‘chkconfig’ command to have ntpd run at boot:
# chkconfig ntp on
NOTE: CORRECT TIME IS IMPORTANT FOR KERBEROS TO FUNCTION CORRECTLY. MAKE SURE NTPD IS RUNNING ON THE SAMBA SERVER AND THAT YOU SET THE WINDOWS CLIENT TO THE MOST ACCURATE TIME POSSIBLE! THE WINDOWS CLIENT TIME SHOULD BE SET TO THE EXACT TIME OF THE SAMBA 4 SERVER WITHIN A FEW SECONDS IF POSSIBLE.
Configure Windows Client to Join Domain
The following will describe how to add a Windows 7 client to the samba DC. For other versions of Windows the same principle should be the same.
To simplify and to limit errors with DHCP, we will assign a static IP address to our Windows 7 client NIC. Configure your network device as follows:
Click ‘OK’ to save the changes.
Now bring up a command prompt in windows and ping the Samba DC:
ping 192.254.77.146
Verify that DNS is working correctly by pinging the FQDN:
ping adhd.ssno.org
If you get replies from both then this is a good sign and should mean that your Samba DC is functional. Also, you may need to reboot Windows for network settings to take effect.
Configure Date, Time and Time Zone on Windows Client
Active Directory uses Kerberos as the backend for authentication. Kerberos requires that the system clocks on the client and server be synchronized to within a few seconds of each other. If they are not synchronized, then authentication will fail for apparently no reason. Adjust your date, time and time zone accordingly on your Windows client to match your Samba 4 server.
Join Windows 7 Client to the Domain
1. Right-click ‘My Computer’ icon and choose ‘Properties’
2. From the left-side pane click ‘Advanced system settings’
3. Choose the ‘Computer Name’ tab and click ‘Change…’
4. Select option ‘Domain’, and insert SSNO.ORG. If this fails just try SSNO.
5. When it requests a username and password, type ‘Administrator’ as the username and then enter your password. (password = the password you used when you ran the ‘samba-tool domain provision’ command)
6. You should get a message box stating ‘Welcome to the SSNO.ORG domain’
7. Click OK on this message box and the Properties window, and you will then be instructed to restart your computer.
8. After restarting you should be presented with the normal login dialog. Click on ‘Switch User’ button.
9. Choose ‘Other user’ and then enter in the following:
Press ‘Enter’ or the arrow button.
10. You should then authenticate and then login to Windows.
Install Windows Remote Administration Tools
To install the GUI tools to manage the domain you must install the Remote Server Administration Tools. This will allow you easily manage the domain using Active Directory.
Windows 7
1. Download the Windows Remote Server Administration Tools
2. Follow the ‘Install RSAT’ instructions
3. Enable the necessary components in ‘Control Panel -> Programs -> Turn Windows features on or off -> Remote Server Administration Tools’
4. You may need to add the Administrative Tools to your start menu. Right-click ‘Start button’ and select ‘Properties -> Start Menu tab – Customize… -> System administrative tools – Display on the All Programs menu’
Managing Samba 4 AD DC from Windows 7 Client
This is beyond the scope of this article. For further information please refer to the Samba4 HOWTO
Configure the Firewall
Once you have been able to successfully have your windows clients attach to your Samba 4 DC, it is prudent to renable the firewall on your Ubuntu Samba 4 DC.
Configure the firewall to have AT LEAST these ports open:
53, TCP & UDP (DNS)
88, TCP & UDP (Kerberos authentication)
135, TCP (MS RPC)
137, UDP (NetBIOS name service)
138, UDP (NetBIOS datagram service)
139, TCP (NetBIOS session service)
389, TCP & UDP (LDAP)
445, TCP (MS-DS AD)
464, TCP & UDP (Kerberos change/set password)
1024, TCP (AD?)
For RSAT tools and extras other ports may need to be opened. Microsoft has a list of the port required which you can find here: http://technet.microsoft.com/en-us/library/dd772723%28WS.10%29.aspx
To setup folder redirection for users and configure offline files that synchronize, please see my article Folder Redirection using Group Policy
Init script for auto start
When rebooting the server, it would be nice if the Samba service would start automatically. The following init.d startup script will take care of that:
# vim /etc/init.d/samba4
#! /bin/sh
### BEGIN INIT INFO
# Provides: samba
# Required-Start: $network $local_fs $remote_fs
# Required-Stop: $network $local_fs $remote_fs
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: start Samba daemons
### END INIT INFO
#
# Start/stops the Samba daemon (samba).
# Adapted from the Samba 3 packages.
#
SAMBAPID=/var/run/samba/samba.pid
# clear conflicting settings from the environment
unset TMPDIR
# See if the daemon and the config file are there
test -x /usr/local/samba/sbin -a -r /usr/local/samba/etc/ || exit 0
. /lib/lsb/init-functions
case “$1” in
start)
log_daemon_msg “Starting Samba 4 daemon” “samba”
if ! start-stop-daemon –start –quiet –oknodo –exec /usr/local/samba/sbin/samba — -D; then
log_end_msg 1
exit 1
fi
log_end_msg 0
;;
stop)
log_daemon_msg “Stopping Samba 4 daemon” “samba”
start-stop-daemon –stop –quiet –name samba $SAMBAPID
# Wait a little and remove stale PID file
sleep 1
if [ -f $SAMBAPID ] && ! ps h `cat $SAMBAPID` > /dev/null
then
# Stale PID file (samba was succesfully stopped),
# remove it (should be removed by samba itself IMHO.)
rm -f $SAMBAPID
fi
log_end_msg 0
;;
restart|force-reload)
$0 stop
sleep 1
$0 start
;;
*)
echo “Usage: /etc/init.d/samba {start|stop|restart|force-reload}”
exit 1
;;
esac
exit 0
#sudo chmod 755 /etc/init.d/samba4
#sudo update-rc.d samba4 defaults
Homefolders for Acitve Directory users
First we need to create a folder where all the Home folders will reside:
sudo mkdir -m 770 /Users
sudo chmod g+s /Users
chown root.users /Users
Next we will add the the following to /usr/local/samba/etc/smb.conf:
[Users]
directory_mode: parameter = 0700
read only = no
path = /Users
csc policy = documents
You can either map that by using net use h: \\samba\Users\%USERNAME% or by adding the same path to the home folder paragraph under the profile tab of the AD user. The home folder will be created automatically if you use the last option.