Wireless Gateway Series User's Guide

ZyAIR Wireless Gateway Series User’s Guide
Getting to Know Your ZyAIR 1-5
PPTP Encapsulation
Point-to-Point Tunneling Protocol (PPTP) is a network protocol that enables secure transfer of data from a
remote client to a private server, creating a Virtual Private Network (VPN) using a TCP/IP-based network.
PPTP supports on-demand, multi-protocol and virtual private networking over public networks, such as the
Internet. Use PPTP to connect to a broadband modem to achieve access to high-speed data networks via a
familiar "dial-up networking" user interface.
Network Address Translation (NAT)
NAT (Network Address Translation - NAT, RFC 1631) allows the translations of multiple IP addresses
used within one network to different IP addresses known within another network.
NAT for Single-IP-address Internet Access
The ZyAIR's SUA (Single User Account) feature allows multiple-user Internet access for the cost of a
single IP account. NAT supports popular Internet applications such as MS traceroute, CuSeeMe, IRC,
RealPlayer, VDOLive, Quake, and PPTP. No configuration is needed to support these applications.
DHCP (Dynamic Host Configuration Protocol)
DHCP (Dynamic Host Configuration Protocol) allows the individual clients (computers) to obtain the
TCP/IP configuration at start-up from a centralized DHCP server. The ZyAIR has built-in DHCP server
capability enabled by default. It can assign IP addresses, an IP default gateway and DNS servers to DHCP
clients. The ZyAIR also acts as a surrogate DHCP server (DHCP Relay) where it relays IP address
assignment from the actual real DHCP server to the clients.
Multicast
Traditionally, IP packets are transmitted in two ways - unicast or broadcast. Multicast is a third way to
deliver IP packets to a group of hosts. IGMP (Internet Group Management Protocol) is the protocol used to
support multicast groups. The latest version is version 2 (see RFC 2236). The ZyAIR supports versions 1
and 2.
IP Alias
IP Alias allows you to partition a physical network into logical networks over the same Ethernet interface.
The ZyAIR supports three logical LAN interfaces via its single physical Ethernet LAN interface with the
ZyAIR itself as the gateway for each LAN network.
IP Policy Routing
IP Policy Routing provides a mechanism to override the default routing behavior and alter packet
forwarding based on the policies defined by the network administrator.