How to fix Windows 10 incoming SMB session being RST'ed

Question

I have computer A and B, both Windows 10 1703 (15063) with all updates installed up to now. I want to view A's SMB shares from B, but B says it cannot connect to A. Further investigation shows A is RSTing B's TCP connections to port 445.

Have tried:

• reboot everything
• allow "File and Printer Sharing" and "HomeGroup" from A's firewall
• resetting firewall of A
• disabling firewall of A
• disabling firewall of router
• connecting using IP address
• using wired or wireless connection
• using Windows 7 or Windows 10 to connect

And nothing works.

Note:

• nc A 445 from a Linux host got immediate RST
• A can connect to other SMB shares
• A didn't show up in net view /all on B but it shows up in Network option in explorer
• visiting \\localhost on A works
• the network A connected to is set to private network

Wireshark capture: (A is .26 and B is .34; left 2 masked column is my LAN IP network number; all masked region on the right are either NetBIOS name of A or IP of A.)

Windows SMB config

Get-SmbServerConfiguration


AnnounceComment                 :
AnnounceServer                  : False
AsynchronousCredits             : 64
AuditSmb1Access                 : False
AutoDisconnectTimeout           : 15
AutoShareServer                 : True
AutoShareWorkstation            : True
CachedOpenLimit                 : 10
DurableHandleV2TimeoutInSeconds : 180
EnableAuthenticateUserSharing   : False
EnableDownlevelTimewarp         : False
EnableForcedLogoff              : True
EnableLeasing                   : True
EnableMultiChannel              : True
EnableOplocks                   : True
EnableSecuritySignature         : False
EnableSMB1Protocol              : True
EnableSMB2Protocol              : True
EnableStrictNameChecking        : True
EncryptData                     : False
IrpStackSize                    : 15
KeepAliveTime                   : 2
MaxChannelPerSession            : 32
MaxMpxCount                     : 50
MaxSessionPerConnection         : 16384
MaxThreadsPerQueue              : 20
MaxWorkItems                    : 1
NullSessionPipes                :
NullSessionShares               :
OplockBreakWait                 : 35
PendingClientTimeoutInSeconds   : 120
RejectUnencryptedAccess         : True
RequireSecuritySignature        : False
ServerHidden                    : True
Smb2CreditsMax                  : 2048
Smb2CreditsMin                  : 128
SmbServerNameHardeningLevel     : 0
TreatHostAsStableStorage        : False
ValidateAliasNotCircular        : True
ValidateShareScope              : True
ValidateShareScopeNotAliased    : True
ValidateTargetName              : True

sc.exe query mrxsmb20

SERVICE_NAME: mrxsmb20
        TYPE               : 2  FILE_SYSTEM_DRIVER
        STATE              : 4  RUNNING
                                (STOPPABLE, NOT_PAUSABLE, IGNORES_SHUTDOWN)
        WIN32_EXIT_CODE    : 0  (0x0)
        SERVICE_EXIT_CODE  : 0  (0x0)
        CHECKPOINT         : 0x0
        WAIT_HINT          : 0x0

sc.exe query lanmanworkstation

SERVICE_NAME: lanmanworkstation
        TYPE               : 30  WIN32
        STATE              : 4  RUNNING
                                (STOPPABLE, PAUSABLE, IGNORES_SHUTDOWN)
        WIN32_EXIT_CODE    : 0  (0x0)
        SERVICE_EXIT_CODE  : 0  (0x0)
        CHECKPOINT         : 0x0
        WAIT_HINT          : 0x0

Answer 1

I had the same problem today, with the exact same wireshark trace.. then I realized that the IP was incorrect, and a Linux server --obviously without SAMBA-- was sending the RST,ACK packets. So the reason could be that :

• You typed the wrong IP / DNS name
• No service listening on server side