Pppoe/Pptp Interfaces Overview; Figure 138 Example: Pppoe/Pptp Interfaces - ZyXEL Communications Unified Security Gateway ZyWALL 1000 User Manual

PPPoE is often used with cable modems and DSL connections. It provides the following
advantages:
• The access and authentication method works with existing systems, including RADIUS.
• You can access one of several network services. This makes it easier for the service
provider to offer the service
• PPPoE does not usually require any special configuration of the modem.
PPTP is used to set up virtual private networks (VPN) in unsecure TCP/IP environments. It
sets up two sessions.
1 The first one runs on TCP port 1723. It is used to start and manage the second one.
2 The second one uses Generic Routing Encapsulation (GRE, RFC 2890) to transfer
information between the computers.
PPTP is convenient and easy-to-use, but you have to make sure that firewalls support both
PPTP sessions.

10.6.2 PPPoE/PPTP Interfaces Overview

In the ZyWALL, you may use PPPoE/PPTP interfaces to connect to your ISP. This way, you
do not have to install or manage PPPoE/PPTP software on each computer in the network.

Figure 138 Example: PPPoE/PPTP Interfaces

PPPoE/PPTP interfaces are similar to other interfaces in some ways. They have an IP address,
subnet mask, and gateway used to make routing decisions; they restrict bandwidth and packet
size; and they can verify the gateway is available. There are two main differences between
PPPoE/PPTP interfaces and other interfaces.
1 You must set up an ISP account before you create a PPPoE/PPTP interface.
Each ISP account specifies the protocol (PPPoE or PPTP), as well as your ISP account
information. If you change ISPs later, you only have to create a new ISP account, not a
new PPPoE/PPTP interface. You should not have to change any network policies.
2 You do not set up the subnet mask or gateway.
PPPoE/PPTP interfaces are interfaces between the ZyWALL and only one computer.
Therefore, the subnet mask is always 255.255.255.255. In addition, the ZyWALL
always treats the ISP as a gateway.
At the time of writing, it is possible to set up the IP address of the gateway (ISP) using CLI
commands but not in the web configurator.
ZyWALL USG 1000 User's Guide
Chapter 10 Interface
211