login to a windows domain from linux

for an NT domain, you should have the following in your smb.conf:
netbios name = SAMBA
workgroup = EVALUESERVE
security = domain
password server = IP_address_of_your_DC

you should then be able to do something like:
smbpasswd -j EVALUESERVE -r IP_address_of_your_DC -U NT_ADMINISTRATOR

Windows Active directory
First, make sure kerberos is installed:
# rpm -qa grep krb
this should return at least 3 packages: krb5-devel, krb5-libs and krb5-workstation Next, make sure the ldap development libraries are installed:
# rpm -qa grep ldap-devel
If either of these returns nothing, you'll need to install them - which you can do from the Redhat CD.
make sure there's an entry for your active directory DC in your /etc/hosts file: 1.2.3.4 addc.example.com addc
Next, edit your /etc/krb5.conf to match your site. Everything should be fairly self-explanitory - and everything is case sensitive. Do not comment this file.
Once you've gotten to this point, you can try:
# /usr/kerberos/bin/kinit user@DOMAIN.COM
replacing *user* with a real user and DOMAIN.COM with a real domain (which must be UPPERCASE). If things are working, you'll be prompted for a password. If you enter the correct password, you'll come back to a bash shell, if not, you should be presented with:
"kinit(v5): Preauthentication failed while getting initial credentials"
or some such.
Note: If the clock time on the Linux machine is more than 5 minutes off from the time on the windows machine no ticket information will work. There are three wys to deal with this:
1. Have the Linux server act as a network time server, with the windows machine as a client
2. Have the windows machine act as a time server for the linux client
3. Make both systems pull the time from the same 3rd server ( some are listed here - http://ntp.isc.org/bin/view/Servers/NTPPoolServers )

Next, uninstall samba if it's installed:
# rpm -e samba
get the latest version of samba:
$ wget http://us1.samba.org/samba/ftp/samba-latest.tar.gz
expand and install samba:
$ tar -zxvf samba*.tar.gz
$ cd samba-3.0.13
$ ./configure --prefix=/usr/local/samba --with-ldap --with-ads --with-krb5 --with-pam --with-winbind
# make && make installIn
your smb.conf:
----8<-----
netbios name = LINUX_SERVER_NAME
realm = DOMAIN.COM ads server = 123.123.123.123
security = ADS
encrypt passwords = yes
----8<-----
start samba:
# /etc/rc.d/init.d/smb start
To add the linux computer to the AD, you need to log into the DC and add it as a user with such privledges, so (from the Linux system):
# /usr/local/samba/bin/net ads join -U Administrator
it should prompt you for Administrator's password. Note that Administrator should be a user with the right to add a computer to the AD.
you should see something like:
Joined 'LINUX_MACHINE_NAME' to realm 'DOMAIN.COM'

To verify this worked, go to the windows DC and open Active Directory->Users and Computers and look for your linux machine to be listed there.
That's all you absolutely need to connect to the AD. If you want to map users to the AD (which is probably why you're doing this), open /etc/nsswitch.conf and change this:
passwd: files
shadow: files
group: files
to this:
passwd: compat winbind
shadow: compat
group: compat winbind
start the winbind daemon:
# winbindd
make sure it's running:
# ps -ae grep winbindd
if nothing gets returned, you probably didn't configure samba with kerberos and ldap support. If it shows winbindd running, you're all set. To make sure everything starts on reboot:
open /etc/rc.d/init.d/smb and /etc/rc.d/init.d/winbindd and make sure the line:
# chkconfig: 345 NN NN exixts (NN will be different numbers pertaining to priority), it should be on line 3 of both files. if these lines don't exist, add them. If they read:
# chkconfig: - NN NN change the - to 345 save and close those files and run chkconfig:
# chkconfig smb reset
# chkconfig winbindd reset you can check the runlevels they will start at with # chkconfig smb --list
# chkconfig winbindd --list
That should about cover everything.