Port blocking like a Firewall (sort of)

[Michael Burns]

Anybody ever try doing this? Basically, blocking TCP
connections by anything, including programs running on the
host machine, to a specific port.

i.e. Making it so that even say, a telnet program can't open
port 23 to connect outward on its own machine?

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Michael Burns
http://www.revise.com

[Ian Cairns]

There is excellent info about this topic on Steve Gibson's site: http://www.grc.com
And although there is no specific information about "building" firewalls, he does provide information regarding ports and vulnerability if you follow the "Shields Up" paths.
regards,

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[email protected]

[This message has been edited by Ian Cairns (edited October 31, 2000).]

[Wayne Diamond]

Ian, would you be kind enough to provide the actual URL? I can't find anything regarding 'how to write firewall software' on his site ?
Many thanks,
Wayne

Hmm I may have to put win2k on this box - does anyone know if the so-called "firewall APIs" of Win2K are any good, from a developers point of view?



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[Michael Burns]

Yes, Gibson's site is interesting for a discussion of firewalls,
and for testing a firewall install.

I use his Shields Up to test my BlackICE installation.

What I'm interested in learning is how to manipulate the
network API. I presume its done using WSP API's. http://msdn.microsoft.com/library/ps...start_9g1e.htm



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Michael Burns
http://www.revise.com

[Wayne Diamond]

Not winsock hooks as such, I believe theyre TDI (Transport Driver Interface) hooks, and there's an good description at http://msdn.microsoft.com/library/pe...d00/VTrace.htm
Not a lot of documentation on this sort of stuff - even VTrace.htm acknowledges that


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