trying to get one server to mount.cifs a share on another and when it failed I used smbclient and it lead me into this oddity and I just can't seem to reason my way through. so you can skim better in case this is too much info: the mystery: why does command #3 work from server1 against itself, but fail for all other clients? server1: samba 3.4.7 (Ubuntu 10.04 server), NT4 domain member with windbind. NT4 domain has an AD domain trust server2: samba 3.6.18 (Ubutnu 13.10 server), AD domain member, with kerberos not winbind. - both servers have "map to guest=bad user" and have a couple shares that allow guests. - all other shares have group based access lists via "user=@groupname" - server2 is on another subnet, fully routable via VPN, ping and ssh work both ways for all systems listed - I was going to wait until Ubuntu 14.04 was final and I tested to upgrade server1's OS, but if all this is a know issue and it'll fix this I can upgrade sooner. This needs to be deployed well before April rolls around. clients: client1: smbclient 4.0.13, a basic server, ubuntu 14.04 packages client2: smbclient 3.6.18, full desktop system, ubuntu 13.10 packages client3: smbclient 3.6.18, a basic server, ubuntu 13.10 packages commands: #1 smbclient -L $server #2 smbclient -L $server -U user -W NT4 #3 smbclient -L $server -U user2 -W AD client1: all 3 commands work as expected against server2. against server1 , 1&2 work, #3 gives NT_STATUS_ACCESS_DENIED client2: all 3 commands work as expected against server2. against server1 , only #1 works, #2&3 gives NT_STATUS_ACCESS_DENIED. Nautilus file manager's smb:// works for server2, does not work for any user for server1. client3: same as client2 smbclient commands from server2 against server1, only #1 works, #2&3 gives NT_STATUS_ACCESS_DENIED smbclient commands from server1 against server2, all commands work. smbclient commands from server1 against itself, all commands work. all window systems in either domain on either subnet work as expected against both servers so again, the mystery: why does #3 work from server1 against itself, but fail for all other clients? server1's logs for one client: [2014/01/06 15:18:22, 5] auth/auth_util.c:208(make_user_info_map) Mapping user [AD]\[user2] from workstation [10.213.0.2] [2014/01/06 15:18:22, 5] auth/auth_util.c:120(make_user_info) attempting to make a user_info for user2 (user2) [2014/01/06 15:18:22, 5] auth/auth_util.c:130(make_user_info) making strings for user2's user_info struct [2014/01/06 15:18:22, 5] auth/auth_util.c:162(make_user_info) making blobs for user2's user_info struct [2014/01/06 15:18:22, 3] auth/auth.c:222(check_ntlm_password) check_ntlm_password: Checking password for unmapped user [AD]\[user2]@[10.213.0.2] with the new password interface [2014/01/06 15:18:22, 3] auth/auth.c:225(check_ntlm_password) check_ntlm_password: mapped user is: [AD]\[user2]@[10.213.0.2] [2014/01/06 15:18:22, 5] ../lib/util/util.c:304(_dump_data) [0000] 5B CE E5 66 DF 66 C0 B3 [..f.f.. [2014/01/06 15:18:22, 6] auth/auth_sam.c:416(check_samstrict_security) check_samstrict_security: AD is not one of my local names (ROLE_DOMAIN_MEMBER) [2014/01/06 15:18:22, 3] smbd/sec_ctx.c:210(push_sec_ctx) push_sec_ctx(0, 0) : sec_ctx_stack_ndx = 1 [2014/01/06 15:18:22, 3] smbd/uid.c:428(push_conn_ctx) push_conn_ctx(0) : conn_ctx_stack_ndx = 0 [2014/01/06 15:18:22, 3] smbd/sec_ctx.c:310(set_sec_ctx) setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1 [2014/01/06 15:18:22, 5] auth/token_util.c:522(debug_nt_user_token) NT user token: (NULL) [2014/01/06 15:18:22, 5] auth/token_util.c:548(debug_unix_user_token) UNIX token of user 0 Primary group is 0 and contains 0 supplementary groups [2014/01/06 15:18:22, 3] smbd/sec_ctx.c:418(pop_sec_ctx) pop_sec_ctx (0, 0) - sec_ctx_stack_ndx = 0 [2014/01/06 15:18:22, 5] auth/auth.c:274(check_ntlm_password) check_ntlm_password: winbind authentication for user [user2] FAILED with error NT_STATUS_ACCESS_DENIED [2014/01/06 15:18:22, 2] auth/auth.c:320(check_ntlm_password) check_ntlm_password: Authentication for user [user2] -> [user2] FAILED with error NT_STATUS_ACCESS_DENIED [2014/01/06 15:18:22, 5] auth/auth_util.c:2114(free_user_info) attempting to free (and zero) a user_info structure [2014/01/06 15:18:22, 3] smbd/error.c:60(error_packet_set) error packet at smbd/sesssetup.c(1725) cmd=115 (SMBsesssetupX) NT_STATUS_ACCESS_DENIED