Windows – When Does the Linux & Windows’ Samba Port Connection Close

connectionsnetstatnetworkingsambawindows

After connecting to a samba share, then disconnecting, netstat still shows that the ports are ESTABLISHED, even when the clients are on SUSPEND, HIBERNATE, or have SHUTDOWN. Looking over the samba documentation, I know now that I can set a period so those ports can TIMEOUT after said time. But without this variable: How long does the

A) Windows (Win 7 x64 Home) connection (445 shown in my case) take to close?

B) Linux (Ubuntu 11.04 x86) connection (139/445 shown in my case) take to close?

Best Answer

To clarify: Before this question, from a pretty much "stock" configuration, I was getting the symptoms shown above. After this question, and some tinkering, I have gotten the time down somehow to disconnect minutes after LOGOUT, ETC.; without the need to resort to the solutions below.

The best, trustworthy, answer I can find is from O'Reilly Online.

SO_KEEPALIVE

This initiates a periodic (four-hour) check to see if the client has disappeared. Expired connections are addressed somewhat better with Samba's keepalive and dead time options. All three eventually arrange to close dead connections, returning unused memory and process-table entries to the operating system.

So basically, it is closed after just 4 hours! But as also said, it's best to use Samba's keepalive option to close this far gap. Of course, even then, since Samba's/Windows's/Etc. ability to close and reopen said ports is of no problem, I will resort to using deadtime instead to just close the unused gap; whether or not the client is still there.

Related Solutions

Windows Networking – How to Check if a Remote Port is Open Using Command Line

I found a hiddem gem the other day from Microsoft that is designed for testing ports:

Portqry.exe

"Portqry.exe is a command-line utility that you can use to help troubleshoot TCP/IP connectivity issues. Portqry.exe runs on Windows 2000-based computers, on Windows XP-based computers, and on Windows Server 2003-based computers. The utility reports the port status of TCP and UDP ports on a computer that you select. "

Samba – Compatibility with Windows When Case-Sensitive Names Are Enabled

It should be fine. Windows Explorer does a fine job of displaying filename case correctly. I use this in my smb.conf to make sure what I type in Explorer is what Samba uses (I set all of these per-share):

case sensitive = True
default case = lower
preserve case = yes
short preserve case = yes

I ran through a quick test (Samba 3.0.24 on the backend, WinXP on the front). Files were created on the samba server via an SSH session.

$ cd /some/samba/share/path
$ mkdir test
$ cd test

$ mkdir test1 TEST1
$ touch test1/foo TEST1/bar

After this, I browsed through my mapped drive to the test directory. I can see both "test1" and "TEST1" directories. I opened "test1" and saw the "foo" file. I opened "TEST1" and saw the "bar" file. So far so good.

Then I went back to the test directory, and in the Explorer window, renamed TEST1 to TEST2. Windows freaked slightly -- it renamed the folder, then showed BOTH folders as TEST2 -- appearing to have renamed both folders. But, in the SSH terminal, I checked:

$ ls
test1 TEST2

So Windows renamed the file, and Samba got the filename correctly. When I pressed F5 in the Explorer window to refresh the folder contents, the display changed to show the correct folder names.

Caveat: Linux filesystems allow some characters that Windows doesn't (like ":"). Samba has a "name mangling" option to turn those filenames into something Windows will like. If I make a file called "FA:23" in my SSH window, for example, Samba mangles the name to "F7T4H0~F" and that's what appears in the Explorer window.

Best Answer

Related Solutions

Windows Networking – How to Check if a Remote Port is Open Using Command Line

Samba – Compatibility with Windows When Case-Sensitive Names Are Enabled

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