Wireshark-users: [Wireshark-users] Windows 7 Ignores TCP MSS?

From: "Robinson, Eric" <eric.robinson@xxxxxxxxx>
Date: Wed, 23 Mar 2011 16:14:34 -0700
I just did a capture of a file transfer from a Windows 7 computer to a Linux FTP server. I can see the Windows client reporting its MSS at 1460. Then I see the FTP server reporting its MSS at 1460. But when the transfer starts, the client sends 2896-byte packets!
 
Following are the settings on the Windows client box.
 
 
C:\>netsh interface ipv4 show subinterface
 
   MTU  MediaSenseState   Bytes In  Bytes Out  Interface
------  ---------------  ---------  ---------  -------------
4294967295                1          0      22655  Loopback Pseudo-Interface 1
  1500                1  271689236  1374564858  Local Area Connection
 

C:\>netsh int tcp show global
Querying active state...
 
TCP Global Parameters
----------------------------------------------
Receive-Side Scaling State          : enabled
Chimney Offload State               : disabled
NetDMA State                        : enabled
Direct Cache Acess (DCA)            : disabled
Receive Window Auto-Tuning Level    : disabled
Add-On Congestion Control Provider  : ctcp
ECN Capability                      : disabled
RFC 1323 Timestamps                 : disabled
 

--
Eric Robinson

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 


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