Receivin packets from the intternet thru router

When I receive packets from the internet on my router machine, the OS
implements the INPUT chain in the iptables modules, if I'm requestin a
webpage (probably forwarded from a LAN machine) what is the destination
port? Is it port 80 or any other port. I know when I'm sending, I send
to port 80 on remote machine but I may send with any port, but when I'm
receiving do I also receive n port 80?

(E-Mail Removed) wrote:
> When I receive packets from the internet on my router machine, the OS
> implements the INPUT chain in the iptables modules, if I'm requestin a
> webpage (probably forwarded from a LAN machine) what is the destination
> port? Is it port 80 or any other port. I know when I'm sending, I send
> to port 80 on remote machine but I may send with any port, but when I'm
> receiving do I also receive n port 80?
>

If you are connecting to a webpage (80), your OS will reserve one port
for this connection on your client side in an OS specific matter. This
port is transmitted to the destination, which then is permanently used.

for example:
54378 (client) <-> 80 (server)

Your router will remember this connection until it is canceled or finished.

Eric

(E-Mail Removed) wrote:
> When I receive packets from the internet on my router machine, the OS
> implements the INPUT chain in the iptables modules, if I'm requestin a
> webpage (probably forwarded from a LAN machine) what is the destination
> port? Is it port 80 or any other port. I know when I'm sending, I send
> to port 80 on remote machine but I may send with any port, but when I'm
> receiving do I also receive n port 80?


Please go to <http://people.netfilter.org/rusty/unreliable-guides/>,
get the guides and read them. It seems that you do not have the
necessary basic information. You need at least the 4 HOWTO documents.

--

Tauno Voipio
tauno voipio (at) iki fi