Internet is a network of networks that consists of millions of private, public, academic, business,and government networks of local to global scope that are linked by a broad array of electronic and optical networking technologies.
The Internet carries a vast array of information resources and services. Different Network elements such as routers, switches, hubs etc.. has been interconnected together for commincation of data over the transmission media.
The routers are connecting the WAN interefaces through the serial ports for data transmission and forwarding the packets using routing tables where as switches and hubs are connecting the LAN.
Static routing tables and dynamic routing protocols tell the routers where to forward IP traffic .
These routers mainly route the data traffic between networks without any filterattion. The job of traffic filtering is best performed by Access Control Lists.
Access list filters the traffic by restricting the packets are to be forwarded or to be blocked at the router’s interfaces.
Router examine each packet and forward or discard the packet based on the information available in the access control list.
Restriction of the traffic can be either source I.P. address, Destination I.P. address, port numbers also
Finally, in the reports trinees has to give different commands on the router on various routing techniques and accesslists to get the require results for connection establishment and troubleshooting of WAN interefaces and LAN networks.