Re: Outgoing port 53 redirected to special port.
> Just for the sake of it and for learning-purposes i would now like to
> build a better wall. The problem is that one computer that they scan
> from is the name-server and that one is hard to isolate it completely
> from here. The only thing i allow from the DNS is UDP from 1024-65535
> since DNS, in case the packets isn't larger than 512 bytes which i
> haven't encountered so far, uses UDP on a port that the program can
> access itself.
>
> What i now would like to do is to organize it so that all the outgoing
> requests to the nameserver goes through a special port. I guess it would
> be done it i set up a nameserver on my own machine that sends the
Wouldn't it be sufficient for this purpose to only accept connections on
those ports which are in reply to a request from your own system? I
thought ipfwadm could do this with the '-k' flag.
> requests which should come back on port 53 but i don't like the idea of
> another large program that takes up my memory.
It's not that big, and you could even make it caching so your lookups
will be a little faster.
Maarten
--
Maarten Boekhold, boekhold@tibco.com
TIBCO Finance Technology Inc.
The Atrium
Strawinskylaan 3051
1077 ZX Amsterdam, The Netherlands
tel: +31 20 3012158, fax: +31 20 3012358
http://www.tibco.com
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