🚀 go-pugleaf

In article <63f39l$pv$1@canada.lmrln.demon.co.uk>,
	pbs@canada.lmrln.demon.co.uk (Philip Shearer) writes:

> I thought that Ip-forwarding and Masquerading were two different concepts
> with Ip-forwarding the packets from the w95 machines will be sent onto
> the Internet with the original IP address of the w95 machines.

Normally, yes.

> With IP Masquerading (using say socks5) then the addresses of the
> original machines will be hidden/translated  by the socks5 software so
> that all packets appear on the internet side to be from the single legal
> IP address on the Linux box running socks5.

socks requires clients to be compiled to understand socks proxies. Linux
supports IP masquerading in the kernel, where packet headers are rewritten
in both directions so the machines behind the firewall don't know they're
not really on the internet.

> Please could someone explain if I am wrong about how IP-forwarding works,
> or confirm what I say if I am correct.

"Forwarding" is a very general term, and so masquerading could be seen as a
type of forwarding, but I agree that if I heard someone talking about
forwarding without qualifying it, I would assume they meant passing the
packets on unmodified.

To get IP masquerading on linux, you have to also turn on IP forwarding, as
without that on it will simply ignore all packets that aren't for it. With
the growth of home ethernets, and without any ISPs offering routed dialups
for sensible (for home use) money, probably the majority of people using the
linux IP forwarding option are in fact doing masquerading.