Samba and Snow Leopard -- slow connects

Does anyone know if there is a root cause and solution to the OS X 10.6 Samba issues? We are seeing very slow connects from 10.6.2 to Windows Server 2003 via samba.

(smbclient connects fast every time)

Any suggestions?

Mac OS X's TCP delayed ack implementation's default mode of operation seems to run afoul of some SMB servers on some networks. Do this:

$ sysctl net.inet.tcp.delayed_ack

...and see if it's set to 3 (the default, at least as of Mac OS X v10.6 "Snow Leopard"). If it is, try setting it to 0 (off):

$ sudo sysctl -w net.inet.tcp.delayed_ack=0

...and re-run your test. You may need to unmount any mounted SMB shares and re-mount them, so that you're creating new TCP connections to the server after changing your Delayed Ack setting.

If that solves the problem, you can make that change automatically take effect on every boot by creating a file:

/etc/sysctl.conf

and have it contain the line:

net.inet.tcp.delayed_ack=0