You have a dedicated internet line in your LAN and IP from your ISP is...

Do the following steps as:

1.iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -p tcp -j SNAT –to-source 202.2.2.2.

POSTROUTINGThis filter point handles packets immediately prior leaving the system.

When Packets leave the system all’s source address change to 202.2.2.2 and can access the internet.

iptables is the build-in firewall tools, used to filter the packets and for nat. By identifying Source Address, Destination Address, type of protocol, source and destination port we can filter the packets.

-sSource Address

-dDestination Address

-pLayer 3 Protocol

-dDestination Address

--sportSource Prot

--dportDestination Port

-iIncoming Interface

-oOutgoing Interface

-tTable either filter or nat or mangle

-AChain can be either INPUT, OUTPUT, FORWARD, PREROUTING, POSTROUTING.