I have this pesky problem with Samba on my Ubuntu 14.04LTS authenticating to Windows 2008. When I run:

net ads join -u <username>, I get "Host is not configured as a member server. Failed to join domain: This operation is only allowed for the PDC of the domain. Here is my krb5.conf and smb.conf

krb5.conf

[libdefaults]
default_realm = CORP.ALPHAOMEGA.COM
default_tgs_enctypes = AES256-CTS AES128-CTS RC4-HMAC DES-CBC-MD5 DES-CBC-CRC
default_tkt_enctypes = AES256-CTS AES128-CTS RC4-HMAC DES-CBC-MD5 DES-CBC-CRC
preferred_enctypes = RC4-HMAC DES-CBC-MD5 DES-CBC-CRC
dns_lookup_kdc = true
pkinit_kdc_hostname = <DNS>
pkinit_anchors = DIR:/var/lib/likewise/trusted_certs
pkinit_cert_match = &&<EKU>msScLogin<PRINCIPAL>
pkinit_eku_checking = kpServerAuth
pkinit_win2k_require_binding = false
pkinit_identities = PKCS11:/usr/lib/likewise-open/libpkcs11.so
default_keytab_name = /etc/krb5.keytab
[domain_realm]
.alphaomeganfs1.corp.alphaomega.com = ALPHAOMEGANFS1.CORP.ALPHAOMEGA.COM
.corp.alphaomega.com = CORP.ALPHAOMEGA.COM
[realms]
ALPHAOMEGANFS1.CORP.ALPHAOMEGA.COM = {
auth_to_local = RULE:[1:$0\$1](^ALPHAOMEGANFS1\.CORP\.ALPHAOMEGA\.COM\\.*)s/^ALPHAOMEGANFS1\.CORP\.ALPHAOMEGA\.COM/ALPHAOMEGANFS1/
auth_to_local = DEFAULT
}
CORP.ALPHAOMEGA.COM = {
auth_to_local = RULE:[1:$0\$1](^CORP\.ALPHAOMEGA\.COM\\.*)s/^CORP\.ALPHAOMEGA\.COM/ALPHAOMEGA/
auth_to_local = DEFAULT
}
[appdefaults]
pam = {
mappings = ALPHAOMEGA\\(.*) $1@CORP.ALPHAOMEGA.COM
forwardable = true
validate = true
}
httpd = {
mappings = ALPHAOMEGA\\(.*) $1@CORP.ALPHAOMEGA.COM
reverse_mappings = (.*)@CORP\.ALPHAOMEGA\.COM ALPHAOMEGA\$1
}

And my smb.conf

[global]

## Browsing/Identification ###

# Change this to the workgroup/NT-domain name your Samba server will part of
workgroup = alphaomega
realm = corp.alphaomega.com
security = ads
os level = 0
domain master = yes
local master = yes
preferred master = yes

# server string is the equivalent of the NT Description field
server string = %h server (Samba, Ubuntu)

# Windows Internet Name Serving Support Section:
# WINS Support - Tells the NMBD component of Samba to enable its WINS Server
# wins support = no

# WINS Server - Tells the NMBD components of Samba to be a WINS Client
# Note: Samba can be either a WINS Server, or a WINS Client, but NOT both
; wins server = w.x.y.z

# This will prevent nmbd to search for NetBIOS names through DNS.
dns proxy = no

#### Networking ####

# The specific set of interfaces / networks to bind to
# This can be either the interface name or an IP address/netmask;
# interface names are normally preferred
; interfaces = 127.0.0.0/8 eth0
; interfaces = 10.190.80.0/24 eth0

# Only bind to the named interfaces and/or networks; you must use the
# 'interfaces' option above to use this.
# It is recommended that you enable this feature if your Samba machine is
# not protected by a firewall or is a firewall itself. However, this
# option cannot handle dynamic or non-broadcast interfaces correctly.
; bind interfaces only = yes
# bind interfaces only = yes



#### Debugging/Accounting ####

# This tells Samba to use a separate log file for each machine
# that connects
log file = /var/log/samba/log.%m

# Cap the size of the individual log files (in KiB).
max log size = 1000

# If you want Samba to only log through syslog then set the following
# parameter to 'yes'.
# syslog only = no

# We want Samba to log a minimum amount of information to syslog. Everything
# should go to /var/log/samba/log.{smbd,nmbd} instead. If you want to log
# through syslog you should set the following parameter to something higher.
syslog = 0

# Do something sensible when Samba crashes: mail the admin a backtrace
panic action = /usr/share/samba/panic-action %d


####### Authentication #######

# Server role. Defines in which mode Samba will operate. Possible
# values are "standalone server", "member server", "classic primary
# domain controller", "classic backup domain controller", "active
# directory domain controller".
#
# Most people will want "standalone sever" or "member server".
# Running as "active directory domain controller" will require first
# running "samba-tool domain provision" to wipe databases and create a
# new domain.
server role = member server

# If you are using encrypted passwords, Samba will need to know what
# password database type you are using.
passdb backend = tdbsam
security = user
obey pam restrictions = yes

# This boolean parameter controls whether Samba attempts to sync the Unix
# password with the SMB password when the encrypted SMB password in the
# passdb is changed.
unix password sync = yes

# For Unix password sync to work on a Debian GNU/Linux system, the following
# parameters must be set (thanks to Ian Kahan <<kahan@informatik.tu-muenchen.de> for
# sending the correct chat script for the passwd program in Debian Sarge).
passwd program = /usr/bin/passwd %u
passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .

# This boolean controls whether PAM will be used for password changes
# when requested by an SMB client instead of the program listed in
# 'passwd program'. The default is 'no'.
pam password change = yes

# This option controls how unsuccessful authentication attempts are mapped
# to anonymous connections
map to guest = bad user

########## Domains ###########

#
# The following settings only takes effect if 'server role = primary
# classic domain controller', 'server role = backup domain controller'
# or 'domain logons' is set
#

# It specifies the location of the user's
# profile directory from the client point of view) The following
# required a [profiles] share to be setup on the samba server (see
# below)
; logon path = \\%N\profiles\%U
# Another common choice is storing the profile in the user's home directory
# (this is Samba's default)
# logon path = \\%N\%U\profile

# The following setting only takes effect if 'domain logons' is set
# It specifies the location of a user's home directory (from the client
# point of view)
; logon drive = H:
# logon home = \\%N\%U

# The following setting only takes effect if 'domain logons' is set
# It specifies the script to run during logon. The script must be stored
# in the [netlogon] share
# NOTE: Must be store in 'DOS' file format convention
; logon script = logon.cmd

# This allows Unix users to be created on the domain controller via the SAMR
# RPC pipe. The example command creates a user account with a disabled Unix
# password; please adapt to your needs
; add user script = /usr/sbin/adduser --quiet --disabled-password --gecos "" %u

# This allows machine accounts to be created on the domain controller via the
# SAMR RPC pipe.
# The following assumes a "machines" group exists on the system
; add machine script = /usr/sbin/useradd -g machines -c "%u machine account" -d /var/lib/samba -s /bin/false %u

# This allows Unix groups to be created on the domain controller via the SAMR
# RPC pipe.
; add group script = /usr/sbin/addgroup --force-badname %g
winbind enum groups = yes
winbind enum users = yes
winbind use default domain = yes
winbind nested groups = yes
winbind refresh tickets = yes
winbind separator = /
allow trusted domains = no
############ Misc ############

# Using the following line enables you to customise your configuration
# on a per machine basis. The %m gets replaced with the netbios name
# of the machine that is connecting
; include = /home/samba/etc/smb.conf.%m

# Some defaults for winbind (make sure you're not using the ranges
# for something else.)
; idmap uid = 10000-20000
; idmap gid = 10000-20000
template shell = /bin/bash
idmap config ALPHAOMEGA : default = yes
idmap config ALPHAOMEGA : backend = ad
idmap config ALPHAOMEGA : range = 10000-20000
idmap config ALPHAOMEGA : base_rid = 0
template homedir = /home/%U
# Setup usershare options to enable non-root users to share folders
# with the net usershare command.

# Maximum number of usershare. 0 (default) means that usershare is disabled.
; usershare max shares = 100

# Allow users who've been granted usershare privileges to create
# public shares, not just authenticated ones
usershare allow guests = yes
smb ports = 139
socket options = IPTOS_LOWDELAY TCP_NODELAY
load printers = no
show add printer wizard = no
printing = bsd
printcap name = /dev/null
disable spoolss = yes
#======================= Share Definitions =======================

# Un-comment the following (and tweak the other settings below to suit)
# to enable the default home directory shares. This will share each
# user's home directory as \\server\username
;[homes]
comment = Home Directories
; browseable = no
browseable = yes
writable = yes
;valid users = %S
# By default, the home directories are exported read-only. Change the
# next parameter to 'no' if you want to be able to write to them.
; read only = yes
read only = no

# File creation mask is set to 0700 for security reasons. If you want to
# create files with group=rw permissions, set next parameter to 0775.
; create mask = 0700
create mask = 0755

# Directory creation mask is set to 0700 for security reasons. If you want to
# create dirs. with group=rw permissions, set next parameter to 0775.
; directory mask = 0700
directory mask = 0755

# By default, \\server\username shares can be connected to by anyone
# with access to the samba server.
# Un-comment the following parameter to make sure that only "username"
# can connect to \\server\username
# This might need tweaking when using external authentication schemes
; valid users = %S

# Un-comment the following and create the netlogon directory for Domain Logons
# (you need to configure Samba to act as a domain controller too.)
;[netlogon]
; comment = Network Logon Service
# path = /home/samba/netlogon
path = /var/lib/samba/sysvol/alphaomega.com/
; guest ok = yes
; read only = yes
read only = no

# Un-comment the following and create the profiles directory to store
# users profiles (see the "logon path" option above)
# (you need to configure Samba to act as a domain controller too.)
# The path below should be writable by all users so that their
# profile directory may be created the first time they log on
;[profiles]
; comment = Users profiles
; path = /home/samba/profiles
; guest ok = no
; browseable = no
; create mask = 0600
; directory mask = 0700
;[sysvol]
;path=/var/lib/samba/sysvol
;read only = no
;passdb backend = tdbsam
;obey pam restrictions = yes
[printers]
comment = All Printers
browseable = no
path = /var/spool/samba
printable = yes
guest ok = no
read only = yes
create mask = 0700

# Windows clients look for this share name as a source of downloadable
# printer drivers
[print$]
comment = Printer Drivers
path = /var/lib/samba/printers
browseable = yes
read only = yes
guest ok = no
# Uncomment to allow remote administration of Windows print drivers.
# You may need to replace 'lpadmin' with the name of the group your
# admin users are members of.
# Please note that you also need to set appropriate Unix permissions
# to the drivers directory for these users to have write rights in it
; write list = root, @lpadmin
[Broker1]
comment = Samba for NFS shares
writable = yes
create mode = 0777
directory mode = 0777
browsable = yes
path = /Broker1

Sorry for the lengthy output. Any help would be appreciated. I am using Samba v4.1.6-Ubuntu

When I type " smbclient -L localhost -n", I get a reply and see all the servers listed.