nanog mailing list archives

Re: I don't need no stinking firewall!


From: Jay Hennigan <jay () west net>
Date: Thu, 07 Jan 2010 22:55:25 -0800

Nenad Andric wrote:
On Tue Jan 05, 2010 at 01:04:01PM -0800, Jay Hennigan <jay () west net> wrote:

Or better:
    - Allow from anywhere port 80 to server port > 1023 established

 Adding "established" brings us back to stateful firewall!

Not really. It only looks to see if the ACK or RST bits are set. This is different from a stateful firewall which memorizes each outbound packet and checks the return for a match source/destination/sequence.

--
Jay Hennigan - CCIE #7880 - Network Engineering - jay () impulse net
Impulse Internet Service  -  http://www.impulse.net/
Your local telephone and internet company - 805 884-6323 - WB6RDV


Current thread: