[Samba] Windows server not responding to Samba requests

[Ivan Voras]

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.