ZyXEL NBG-419N Guia Do Utilizador

Página de 298
 Chapter 12 WAN
NBG-419N User’s Guide
121
WAN MAC Address
The MAC address screen allows users to configure the WAN port's MAC address by 
either using the factory default or cloning the MAC address from a computer on 
your LAN. Choose Factory Default to select the factory assigned default MAC 
Address.
Otherwise, click Clone the computer's MAC address - IP Address and enter 
the IP address of the computer on the LAN whose MAC you are cloning. Once it is 
successfully configured, the address will be copied to configuration file. It is 
recommended that you clone the MAC address prior to hooking up the WAN Port.
12.3.2  Multicast
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 delivers IP packets to a group of hosts on the network - not everybody 
and not just 1. 
Figure 79   Multicast Example
In the multicast example above, systems A and D comprise one multicast group. 
In multicasting, the server only needs to send one data stream and this is 
delivered to systems A and D. 
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. The 
NBG-419N supports both IGMP version 1 (IGMP-v1) and IGMP version 2 (IGMP-
v2
). 
At start up, the NBG-419N queries all directly connected networks to gather group 
membership. After that, the NBG-419N periodically updates this information. IP 
multicasting can be enabled/disabled on the NBG-419N LAN and/or WAN