Hi All, I have been using Samba 4.15 on CentOS 6.3 64 bit for last 3 months with no issues but suddenly there i am facing below issues. 1. Windows 7 Pro/Ultimate cannot join the domain, but can telnet all the port. 2. Shared resources on Server 2003 which is added to domain is available some time and some time not. For isolating the issue I have temporary removed the server from Domain the error i get when i try to access shared resources from run is http://3.bp.blogspot.com/-z_PiUex9rI8/Tvll0M4Q0FI/AAAAAAAAAHQ/zxpHzca90bs/s1600/error.jpg. and now I am not facing any issue as of now Below is the wireshark log when i am attempting to join the domain. $ tshark host 192.168.1.253 Running as user "root" and group "root". This could be dangerous. Capturing on eth0 0.000000 192.168.1.253 -> 192.168.10.16 DNS 89 Standard query 0xb88b SRV _ldap._tcp.dc._msdcs.ik.local 0.000176 192.168.10.16 -> 192.168.1.253 DNS 112 Standard query response 0xb88b SRV 0 100 389 dc.ik.local 0.003773 192.168.1.253 -> 192.168.10.16 DNS 71 Standard query 0xd961 A dc.ik.local 0.003930 192.168.10.16 -> 192.168.1.253 DNS 87 Standard query response 0xd961 A 192.168.10.16 0.008004 192.168.1.253 -> 192.168.10.16 CLDAP 161 searchRequest(1) "<ROOT>" baseObject 0.009669 192.168.10.16 -> 192.168.1.253 CLDAP 168 searchResEntry(1) "<ROOT>" searchResDone(1) success 7.488021 192.168.1.253 -> 192.168.10.16 CLDAP 161 searchRequest(2) "<ROOT>" baseObject 7.489684 192.168.10.16 -> 192.168.1.253 CLDAP 168 searchResEntry(2) "<ROOT>" searchResDone(2) success 7.893965 192.168.1.253 -> 192.168.10.16 DNS 89 Standard query 0xfa82 SRV _ldap._tcp.dc._msdcs.ik.local 7.894136 192.168.10.16 -> 192.168.1.253 DNS 112 Standard query response 0xfa82 SRV 0 100 389 dc.ik.local $ telnet <domain ip> 53 --> from client $ tshark host 192.168.1.253 --> at server 91.083022 192.168.1.253 -> 192.168.10.16 TCP 60 49215 > domain [FIN, ACK] Seq=11 Ack=1 Win=65536 Len=0 91.083178 192.168.10.16 -> 192.168.1.253 TCP 54 domain > 49215 [FIN, ACK] Seq=1 Ack=12 Win=14720 Len=0 91.085382 192.168.1.253 -> 192.168.10.16 TCP 60 49215 > domain [ACK] Seq=12 Ack=2 Win=65536 Len=0 $ telnet <domain ip> 445 --> from client $ tshark host 192.168.1.253 --> at server 106.929307 192.168.1.253 -> 192.168.10.16 TCP 66 49216 > microsoft-ds [SYN] Seq=0 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1 106.929319 192.168.10.16 -> 192.168.1.253 TCP 66 microsoft-ds > 49216 [SYN, ACK] Seq=0 Ack=1 Win=14600 Len=0 MSS=1460 SACK_PERM=1 WS=128 106.950451 192.168.1.253 -> 192.168.10.16 TCP 60 49216 > microsoft-ds [ACK] Seq=1 Ack=1 Win=65536 Len=0 116.266820 192.168.1.253 -> 192.168.10.16 NBSS 60 NBSS Continuation Message Also all other ports can be telnet If I restart the domain i can join the domain immediately. I will provide the tshark report of success. Note: FYI There is a firewall in middle. I am facing this issue for last 1 week. I have increase the log level but do not find any errors. Any help will appreciated. Commands Output $ samba-tool dbcheck Checking 957 objects Checked 957 objects (0 errors) $ samba-tool testparm Press enter to see a dump of your service definitions # Global parameters [global] workgroup = IK realm = IK.LOCAL netbios name = DC server role = active directory domain controller log level = 0 syslog = 0 log file = /var/log/samba/log.%m printcap name = /dev/null dns forwarder = 192.168.1.1 idmap_ldb:use rfc2307 = yes [netlogon] path = /usr/local/samba/var/locks/sysvol/ik.local/scripts read only = No [sysvol] path = /usr/local/samba/var/locks/sysvol read only = No [Profiles] path = /srv/samba/Profiles/ read only = No create mask = 0600 directory mask = 0700 profile acls = Yes store dos attributes = Yes csc policy = disable thanks vikas