http://www.dslreports.com/forum/Re-Wireless-question-22444161 en Sat, 11 Feb 2012 16:49:33 EDT Sat, 11 Feb 2012 16:49:33 EDT http://www.dslreports.com/forum/Re-Wireless-question-22449923 said! Seriously, I have yet to see such a concise and complete description of how many times and different ways Windows leaks the Hostname/Machine name.

It's somewhat amazing, actually. What I really love is how many different services actually grab that string differently. It differs from router to router but is almost always used to provide some sort of client "hostname."

Just change it to something ambiguous and you should be set.
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You also have the infamous "NetBIOS" services on UDP 137 and 138 (and optionally TCP 139 which is more or less replaced via TCP 445 these days). These are legacy NetBIOS service enumeration / discovery methods for NetBIOS name suffixes (which denote the service type, whether it's a Workstation service, a PDC, etc.) which generally aren't useful unless you're running an NT 4.0 domain (almost no one these days) or you need your internal network to announce itself in such a manner due to the lack of centralized service enumeration methods (such as DNS SRV records). The Browser service on UDP 138 is there to help populate your "network neighborhood" browse list as well as help in the selection of a Master Browser, etc. (in the NetBIOS sense). All the NetBIOS stuff can be disabled under your interface's IP properties under Advanced -> WINS. You'll need to do this for each individual interface.

SMB / CIFS connections are under the "File and Printer Sharing" option, but there really isn't a "leak" in this sense since having a network share doesn't mean the machine broadcasts its availability.

Windows also tends to give itself away when you have SSDP involved running over UDP 1900. You can look that up. In Vista, you also have Link Layer Topology Discovery and other IPv6 stuff which clutters the network, although it's nice to help draw a network route diagram at a basic level.]]> http://www.dslreports.com/forum/Re-Wireless-question-22448967 Tue, 26 May 2009 21:58:58 EDT http://www.dslreports.com/forum/Re-Wireless-question-22448597 said by nwrickert:

Sending the name seems to be a windows kind of thing.

I mostly run linux, with a statically defined IP address, and the router does not know the machine name. But when I occasionally boot to Windows, and use the same static IP address, the router knows my machine name (I use a different machine name under Windows, so I can tell it is Windows sending that).

You might be able to block all dhcp requests in a software firewall. But you would have to assign a static IP to do that. So it isn't very practical when using wireless, since you are often using wireless on networks that you don't control and must depend on DHCP to assign the IP.
I wonder how one blocks Windows' name then. I know nbtstat can used if one knows the address and stuff.
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Ant @ »antfarm.ma.cx and »aqfl.net. Please do not IM/e-mail me for technical support. Use the forum! Disclaimer: The views expressed in this posting are mine, and do not necessarily reflect the views of my employer]]> http://www.dslreports.com/forum/Re-Wireless-question-22448597 Tue, 26 May 2009 20:49:32 EDT http://www.dslreports.com/forum/Re-Wireless-question-22448520
I mostly run linux, with a statically defined IP address, and the router does not know the machine name. But when I occasionally boot to Windows, and use the same static IP address, the router knows my machine name (I use a different machine name under Windows, so I can tell it is Windows sending that).

You might be able to block all dhcp requests in a software firewall. But you would have to assign a static IP to do that. So it isn't very practical when using wireless, since you are often using wireless on networks that you don't control and must depend on DHCP to assign the IP.
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AT&T dsl; Westell 327w modem/router; openSuSE 11.0; firefox 3.0.10]]> http://www.dslreports.com/forum/Re-Wireless-question-22448520 Tue, 26 May 2009 20:30:05 EDT http://www.dslreports.com/forum/Re-Wireless-question-22448185 said by nwrickert:

If your system then uses DHCP to request an IP address, there is a good likelihood that your software will send your machine name to the DHCP server. It might perhaps also send the IP address most recently used (requesting that it be able to continue to use that). Presumably you could change your machine's name before connecting to the hotspot, and change it back later.Can that be blocked with a firewall/software or is it required?
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Ant @ »antfarm.ma.cx and »aqfl.net. Please do not IM/e-mail me for technical support. Use the forum! Disclaimer: The views expressed in this posting are mine, and do not necessarily reflect the views of my employer]]> http://www.dslreports.com/forum/Re-Wireless-question-22448185 Tue, 26 May 2009 19:12:26 EDT http://www.dslreports.com/forum/Re-Wireless-question-22444205
I suppose you could probably set a different MAC address, but that's probably not worth the trouble.

If your system then uses DHCP to request an IP address, there is a good likelihood that your software will send your machine name to the DHCP server. It might perhaps also send the IP address most recently used (requesting that it be able to continue to use that). Presumably you could change your machine's name before connecting to the hotspot, and change it back later.
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AT&T dsl; Westell 327w modem/router; openSuSE 11.0; firefox 3.0.10]]> http://www.dslreports.com/forum/Re-Wireless-question-22444205 Tue, 26 May 2009 07:14:31 EDT http://www.dslreports.com/forum/Wireless-question-22444161 http://www.dslreports.com/forum/Wireless-question-22444161 Tue, 26 May 2009 06:40:32 EDT