Networking Case Study
Chapter Introduction
1
1.1 Introduction
The task of the assignment is to configure a fully work network for company XYZ. The company XYZ currently has two main offices located in London and in Glasgow. Also near the London based office is the existing ISP connection.
A list of specifications was supplied in order to complete the assignment. The following features were needed to make sure the network worked efficiently:
EIGRP
Frame Relay
DHCP
Network security (NAT & PAT)
The rest of this report will explain in detail the setup of the network and its main features. It will also show a copy of the router configurations that were used to set up the network.
The configurations for the network setup have been appendix at the end of the report.
Chapter Network Address Translation (NAT)
2
2.1 What is NAT?
Network Address Translation (NAT) is an IETF standard that enables a local area network (LAN) to use one set of IP addresses for internal traffic and a second set of addresses for external traffic. All necessary IP address translations occur where the LAN interfaces with the broader Internet. NAT converts the packet headers (and in some cases the port numbers in the headers) for incoming and outgoing traffic and keeps track of each session. This does mean, however, that NAT overrides "Internet transparency", a practice in which packets remain intact throughout their transmission. NAT is also provided with Windows Internet Connection Sharing.
NAT also acts as a firewall by hiding internal IP addresses, and allows an enterprise to bundle multiple ISDN connections into one Internet connection.
Below is a diagram showing how NAT translate traffic coming into and leaving the private network:
Diagram taken from http://www.howstuffworks.com
The benefits of using NAT are;
It eliminates the need to readdress all internal hosts that require access to the external network. This in return saves time and ultimately
1
1.1 Introduction
The task of the assignment is to configure a fully work network for company XYZ. The company XYZ currently has two main offices located in London and in Glasgow. Also near the London based office is the existing ISP connection.
A list of specifications was supplied in order to complete the assignment. The following features were needed to make sure the network worked efficiently:
EIGRP
Frame Relay
DHCP
Network security (NAT & PAT)
The rest of this report will explain in detail the setup of the network and its main features. It will also show a copy of the router configurations that were used to set up the network.
The configurations for the network setup have been appendix at the end of the report.
Chapter Network Address Translation (NAT)
2
2.1 What is NAT?
Network Address Translation (NAT) is an IETF standard that enables a local area network (LAN) to use one set of IP addresses for internal traffic and a second set of addresses for external traffic. All necessary IP address translations occur where the LAN interfaces with the broader Internet. NAT converts the packet headers (and in some cases the port numbers in the headers) for incoming and outgoing traffic and keeps track of each session. This does mean, however, that NAT overrides "Internet transparency", a practice in which packets remain intact throughout their transmission. NAT is also provided with Windows Internet Connection Sharing.
NAT also acts as a firewall by hiding internal IP addresses, and allows an enterprise to bundle multiple ISDN connections into one Internet connection.
Below is a diagram showing how NAT translate traffic coming into and leaving the private network:
Diagram taken from http://www.howstuffworks.com
The benefits of using NAT are;
It eliminates the need to readdress all internal hosts that require access to the external network. This in return saves time and ultimately
Bibliography: 6 The following materials were used to complete this assignment: CCNA 1 And 2 Companion Guide – ISBN 1587131501 CCNA 3 And 4 Companion Guide – ISBN 1587131145 Wide Area Networks IV – Student Lab Manual 2005-2006