ZyXEL N4100 User Guide - Page 69

How iPnP Works, System Setup, N4100 User's Guide

Page 69 highlights

Chapter 4 System Setup 4.3.2 How iPnP Works Address Resolution Protocol (ARP) is a protocol for mapping an Internet Protocol address (IP address) to a physical machine address, also known as a Media Access Control or MAC address, on the local area network. IP routing table is defined on IP Ethernet devices (the N4100) to decide which hop to use, to help forward data along to its specified destination. The following lists out the steps taken, when a computer tries to access the Internet for the first time through the N4100. 1 When a computer (which is in a different subnet) first attempts to access the Internet, it sends packets to its default gateway (which is not the N4100) by looking at the MAC address in its ARP table. 2 When the computer cannot locate the default gateway, an ARP request is broadcast on the LAN. 3 The N4100 receives the ARP request and replies to the computer with its own MAC address. 4 The computer updates the MAC address for the default gateway to the ARP table. Once the ARP table is updated, the computer is able to access the Internet through the N4100. 5 When the N4100 receives packets from the computer, it creates an entry in the IP routing table so it can properly forward packets intended for the computer. After all the routing information is updated, the computer can access the N4100 and the Internet as if it is in the same subnet as the N4100. N4100 User's Guide 69

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Chapter 4 System Setup
N4100 User’s Guide
69
4.3.2
How iPnP Works
Address Resolution Protocol (ARP) is a protocol for mapping an Internet Protocol
address (IP address) to a physical machine address, also known as a Media Access
Control or MAC address, on the local area network. IP routing table is defined on
IP Ethernet devices (the N4100) to decide which hop to use,
to help forward data
along to its specified destination.
The following lists out the steps taken, when a computer tries to access the
Internet for the first time through the N4100.
1
When a computer (which is in a different subnet) first attempts to access the
Internet, it sends packets to its default gateway (which is not the N4100) by
looking at the MAC address in its ARP table.
2
When the computer cannot locate the default gateway, an ARP request is
broadcast on the LAN.
3
The N4100 receives the ARP request and replies to the computer with its own MAC
address.
4
The computer updates the MAC address for the default gateway to the ARP table.
Once the ARP table is updated, the computer is able to access the Internet
through the N4100.
5
When the N4100 receives packets from the computer, it creates an entry in the IP
routing table so it can properly forward packets intended for the computer.
After all the routing information is updated, the computer can access the N4100
and the Internet as if it is in the same subnet as the N4100.