Re: How to not receive a TCP packet...

Neal Cardwell (cardwell@cs.washington.edu)
Mon, 17 Aug 1998 11:05:10 -0700 (PDT)

Would it be possible to use firewall features (in FreeBSD or Linux) to
drop TCP packets coming from the IP address of the machine with which
you're having the dialogue? If not a traditional firewall, then maybe
Dummynet? (http://www.iet.unipi.it/~luigi/ip_dummynet/)

neal

On Mon, 17 Aug 1998, Stefan Savage wrote:

> After further study, I've found that Eric is correct and my DONTROUTE
> hack (as I described in last weeks meeting) only works on the local net.
> Therefore, while it is adequate for testing tools, it doesn't give
> access to remote sights. The other two options are Eric's hack (get
> another IP address and proxy arp for it...) or doing a kernel hack to
> allow TCP packets to be ignored when my filter recognizes them (so as
> not to send a RST). Anyway, I don't particular like any of these ideas.
> The kernel hack isn't very portable, and Eric's hack has the problem
> that it requires the user to get another IP address (and we know how
> hard that is to do some places.... I suppose we could add a DHCP
> implementation, but then the tool starts to become absurdly
> complicated). If anyone has some new ideas about how to handle this I'm
> listening.... otherwise I may do the kernel hack to start with, just
> because its easier.
>
> - Stefan
>