CCNA Cisco Certified Network Associate Study Guide - FTP Server

390 Chapter 8 � Configuring Novell IPX
FIGURE 8.2 Remote IPX clients on a serverless network
NetWare
file server
SAP
In this figure, you can see client workstations at the remote office site: they
require access to server resources at the main office. In this situation, Router
B would answer client GNS requests from its SAP table rather than forwarding
the request across the WAN to the main office servers. The clients never
realize or care that there isn’t a NetWare server present on their LAN.
This communication insulates the client from the task of locating and
tracking available network resources; it places that burden on the server
instead. The client simply broadcasts a GNS and waits for a reply. From the
client’s perspective, all network resources respond as though they were local,
regardless of their physical location in the internetwork.
Server-Server Communication
Router A
SAP
GNS request
GNS reply
Router B
Communication between two NetWare servers is a bit more complicated
than client-server communication. As mentioned earlier, servers are responsible
for maintaining tables of all available network resources, regardless of
whether those resources are local to the server. Also, keep in mind that each
server must be able to locate any resource on the internetwork.
Servers exchange two types of information using two separate protocols:
SAP (Service Advertising Protocol) and RIP (Routing Information Protocol).
As their names suggest, SAP communicates service information, and RIP
communicates routing information.