Chapter 4 Setting The Lan Ip Address; What Is The Lan Ip Address; Igmp - ZyXEL Communications Prestige 623 series User Manual

This chapter describes how to change the Prestige's LAN IP address, or configure it to be
4.1

What is the LAN IP Address?

Your Prestige communicates with your network through its LAN port. To allow for Internet
communication, the LAN port must be identified by a unique IP address, like your computers. The IP
address associated with this port is called the LAN IP address.
The public IP address assigned to you by your ISP is not your LAN IP address.
The public IP address identifies the WAN (ADSL) port on your Prestige to the
Your Prestige is pre-configured with a default LAN IP address of 192.168.1.1. You can change the default
address to reflect the set of IP addresses that you want to use with your network.
You can also configure the Prestige to use a LAN IP address that is assigned dynamically from a DHCP
server on your network. When IP information is assigned by another device, the Prestige is said to be acting
as a DHCP client of that device.
The Prestige itself can function as a DHCP server for your LAN computers, as
described in later chapters, but not for its own LAN port.
4.2

IGMP

Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender – 1 recipient) or
Broadcast (1 sender – everybody on the network). Multicast is a third way to deliver IP packets to a group
of hosts on the network - not everybody.
IGMP (Internet Group Multicast Protocol) is a network-layer protocol used to establish membership in a
multicast group - it is not used to carry user data. IGMP version 2 (RFC 2236) is an improvement over
version 1 (RFC 1112) but IGMP version 1 is still in wide use. If you would like to read more detailed
information about interoperability between IGMP version 2 and version 1, please see sections 4 and 5 of
RFC 2236. The class D IP address is used to identify host groups and can be in the range 224.0.0.0 to
239.255.255.255. The address 224.0.0.0 is not assigned to any group and is used by IP multicast computers.
The address 224.0.0.1 is used for query messages and is assigned to the permanent group of all IP hosts
Setting the LAN IP Address
Setting the LAN IP Address
Internet.
Prestige 623 Series Dual-link ADSL Router
Chapter 4
assigned automatically.
4-1