ZyXEL Communications P-660N-T1A, Руководство пользователя

Страница: 68 / 322

Chapter 6 WAN Setup
P-660N-T1A User’s Guide
68
they should also provide a username and password (and service name) for user
authentication.
WAN IP Address
The WAN IP address is an IP address for the ZyXEL Device, which makes it
accessible from an outside network. It is used by the ZyXEL Device to
communicate with other devices in other networks. It can be static (fixed) or
dynamically assigned by the ISP each time the ZyXEL Device tries to access the
Internet.
If your ISP assigns you a static WAN IP address, they should also assign you the
subnet mask and DNS server IP address(es) (and a gateway IP address if you use
the Ethernet or ENET ENCAP encapsulation method).
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 one.
IGMP
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.
There are three versions of IGMP. IGMP version 2 and 3 are improvements over
version 1, but IGMP version 1 is still in wide use.
Finding Out More
See Section 6.4 on page 78 for technical background information on WAN.
6.1.3 Before You Begin
You need to know your Internet access settings such as encapsulation and WAN IP
address. Get this information from your ISP.