This is a strange problem and it is almost certainly a consequence of faulty Windows server configuration but as it is not under my jurisdiction I need a firm starting point before asking the Windows admin to start digging for the problem. The situation is, as far as I know, this: Win2003 AD with a backup domain controller, and a Win2008 R2 file server. There are a large number of users with roaming profiles and home directories on the file server. From the Windows side, everything apparently works fine: there is a mix of WinXP and Win7 client machines which access both information and mount the home directory without problems. I think there is a DFS-like configuration so the requests for //domain.org/share are forwarded (as far as I understand DFS) to //fileserver.domain.org/share but trying both forms fails in the same way. The problem is that logging into the file server with domain user credentials works fine, but anything else (e.g. "ls") fails in a weird way: apparently the server doesn't respond to the request. The messages from smbclient are: Receiving SMB: Server stopped responding Call timed out: server did not respond after 20000 milliseconds listing \1989\t\test2\* Using "smbclient -d10" basically confirms this - the server doesn't really respond, and there are messages like: write_socket(10,146) write_socket(10,146) wrote 146 read_fd_with_timeout: timeout read. select timed out. receive_smb_raw: NT_STATUS_IO_TIMEOUT! client_receive_smb failed Running tcpdump to trace the connection shows some chatter between the file server and the smbclient, including this response (I don't know if it's significant): 12:14:34.739478 IP (tos 0x0, ttl 128, id 15402, offset 0, flags [DF], proto TCP (6), length 91) fileserver.domain.org.microsoft-ds > client.domain.org.25621: Flags [P.], cksum 0xf7ac (correct), seq 1272:1311, ack 1214, win 256, options [nop,nop,TS val 282282628 ecr 609554], length 39 SMB PACKET: SMBtrans2 (REPLY) SMB Command = 0x32 Error class = 0x57 Error code = 49152 (0xc000) Flags1 = 0x88 Flags2 = 0x1 Tree ID = 16385 (0x4001) Proc ID = 2248 (0x8c8) UID = 24577 (0x6001) MID = 9 (0x9) Word Count = 0 (0x0) NTError = STATUS_PATH_NOT_COVERED TRANSACT2_QPATHINFO Trans2Interim but there is *really* no response to the client's last request (which is repeated several times in various timeouts), which is this: 12:14:36.632956 IP (tos 0x0, ttl 64, id 13920, offset 0, flags [DF], proto TCP (6), length 168) client.domain.org.48525 > fileserver.domain.org.microsoft-ds: Flags [P.], , seq 1036:1152, ack 1178, win 8326, options [nop,nop,TS val 610021 ecr 282281589], length 116 SMB PACKET: SMBtrans2 (REQUEST) SMB Command = 0x32 Error class = 0x0 Error code = 0 (0x0) Flags1 = 0x8 Flags2 = 0x1 Tree ID = 4105 (0x1009) Proc ID = 2248 (0x8c8) UID = 4099 (0x1003) MID = 9 (0x9) Word Count = 15 (0xf) TRANSACT2_FINDFIRST param_length=44 data_length=0 TotParam=44 (0x2c) TotData=0 (0x0) MaxParam=10 (0xa) MaxData=16644 (0x4104) MaxSetup=0 (0x0) Flags=0x0 TimeOut=0 (0x0) Res1=0x0 ParamCnt=44 (0x2c) ParamOff=68 (0x44) DataCnt=0 (0x0) DataOff=112 (0x70) SetupCnt=1 (0x1) smb_bcc=47 Attribute=HIDDEN SYSTEM DIR SearchCount=1366 (0x556) Flags=0x6 Level=260 (0x104) File=\1989\t\test2\* i.e. the server doesn't respond to FindFirstFile(). I have no idea where to go from here.