Netopia 6.3 - Manual (Page 17)

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Section 3 General
Wide Area Network
DHCP ( Dynamic Host Configuration Protocol ) Client
DHCP Client functionality enables the Gateway to request an IP address
from your Service Provider. DHCP servers on your Service Provider’s net-
work reply to DHCP Client requests and assign the network parameters.
PPPoE ( Point-to-Point Protocol over Ethernet )
The PPPoE specification, incorporating the PPP and Ethernet standards,
allows your computer(s) to connect to your Service Provider’s network
through your Ethernet WAN connection. The Netopia Cayman-series Gate-
way supports PPPoE, eliminating the need to install PPPoE client software
on any LAN computers.
Service Providers may require the use of PPP authentication protocols such
as Challenge Handshake Authentication Protocol (CHAP) or Password
Authentication Protocol (PAP). CHAP and PAP use a username and pass-
word pair to authenticate users with a PPP server.
A CHAP authentication process works as follows:
1. The password is used to scramble a challenge string.
2. The password is a shared secret, known by both peers.
3. The unit sends the scrambled challenge back to the peer.
PAP, a less robust method of authentication, sends a username and pass-
word to a PPP server to be authenticated. PAP’s username and password
pair are not encrypted, and therefore, sent “unscrambled”.
Instant-On PPP
You can configure your Gateway for one of two types of Internet connec-
tions:
• Always On
• Instant On
These selections provide either an uninterrupted Internet connection or an
as-needed connection.
While an Always On connection is convenient, it does leave your network
permanently connected to the Internet, and therefore potentially vulnera-
ble to attacks.
Cayman's Instant On technology furnishes almost all the benefits of an
Always-On connection while providing two additional security benefits:
• Your network cannot be attacked when it is not connected.