Chapter 21 Bridging Setup; Bridging In General; Ip Address Assignment; Ip Assignment With Pppoa Or Pppoe Encapsulation - ZyXEL Communications Prestige 861H-G1 User Manual

Prestige 861H User's Guide
Chapter 21
Bridging Setup
This chapter shows you how to configure the bridging parameters of your Prestige.

21.1 Bridging in General

Bridging bases the forwarding decision on the MAC (Media Access Control), or hardware
address, while routing does it on the network layer (IP) address. Bridging allows the Prestige to
transport packets of network layer protocols that it does not route, for example, SNA, from one
network to another. The caveat is that, compared to routing, bridging generates more traffic for
the same network layer protocol, and it also demands more CPU cycles and memory.
For efficiency reasons, do not turn on bridging unless you need to support protocols other than IP
on your network. For IP, enable the routing if you need it; do not bridge what the Prestige can
route.

21.2 IP Address Assignment

A static IP is a fixed IP that your ISP gives you. A dynamic IP is not fixed; the ISP assigns you a
different one each time. The Single User Account feature can be enabled or disabled if you have
either a dynamic or static IP. However the encapsulation method assigned influences your choices
for IP address and ENET ENCAP Gateway.

21.2.1 IP Assignment with PPPoA or PPPoE Encapsulation

If you have a dynamic IP, then the IP Address and ENET ENCAP Gateway fields are not
applicable (N/A). If you have a static IP, then you only need to fill in the IP Address field and not
the ENET ENCAP Gateway field.

21.2.2 IP Assignment with RFC 1483 Encapsulation

In this case the IP Address Assignment must be static with the same requirements for the IP
Address and ENET ENCAP Gateway fields as stated above.

21.2.3 IP Assignment with ENET ENCAP Encapsulation

In this case you can have either a static or dynamic IP. For a static IP you must fill in all the IP
Address and ENET ENCAP Gateway fields as supplied by your ISP. However for a dynamic IP,
the Prestige acts as a DHCP client on the WAN port and so the IP Address and ENET ENCAP
Gateway fields are not applicable (N/A) as the DHCP server assigns them to the Prestige.

21.2.4 Private IP Addresses

Every machine on the Internet must have a unique address. If your networks are isolated from the
Internet, for example, only between your two branch offices, you can assign any IP addresses to
Bridging Setup 21-1