I installed squid and iptables on my redhat 9 box. This box is connected to
internet and to the Lan.
The client browsers in the Lan point to the squid server.
The IP masquerading is also installed.

I know squid is a proxy with cache and acl list, while iptables is a
firewall mainly blocking access from internet.

Now i'm confused with which software does actually perform the IP
masquerading, because:

when i stop squid but not iptables, no client in the Lan can access
internet, but
when i stop iptables but not squid, any client has access to internet.
So i conclude that squid is responsible for the IP masquerading, but in all
documentation, i read is iptables doing that.

Any explanation would be welcome ...