ZyXEL Communications P-2304R, Руководство пользователя

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P-2304R-P1 Series User’s Guide
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H A P T E R
6
WAN
Use these screens to set up the ZyXEL Device on the WAN. You can configure the Internet
connection, DNS servers, and how the ZyXEL Device sends routing information using RIP. In
addition, you can set up a backup gateway in case the default gateway is not available.
6.1 WAN Overview
6.1.1 PPPoE Encapsulation
The ZyXEL Device supports PPPoE (Point-to-Point Protocol over Ethernet). PPPoE is an
IETF standard (RFC 2516) specifying how a personal computer (PC) interacts with a
broadband modem (DSL, cable, wireless, etc.) connection. The
PPP over Ethernet option is
for a dial-up connection using PPPoE.
For the service provider, PPPoE offers an access and authentication method that works with
existing access control systems (for example Radius).
One of the benefits of PPPoE is the ability to let you access one of multiple network services,
a function known as dynamic service selection. This enables the service provider to easily
create and offer new IP services for individuals.
Operationally, PPPoE saves significant effort for both you and the ISP or carrier, as it requires
no specific configuration of the broadband modem at the customer site.
By implementing PPPoE directly on the ZyXEL Device (rather than individual computers),
the computers on the LAN do not need PPPoE software installed, since the ZyXEL Device
does that part of the task. Furthermore, with NAT, all of the LANs’ computers will have
access.
6.1.2 WAN IP Address Assignment
Every computer on the Internet must have a unique IP address. If your networks are isolated
from the Internet, for instance, only between your two branch offices, you can assign any IP
addresses to the hosts without problems. However, the Internet Assigned Numbers Authority
(IANA) has reserved the following three blocks of IP addresses specifically for private
networks.
Table 29 Private IP Address Ranges
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255