network resources that it's aware of. (We'll explain how they do this a bit
later in the chapter.) When clients require access to a certain resource, they
issue an IPX broadcast called a
client needs. In turn, the servers receiving the GNS check their SAP tables
to locate a NetWare server that matches the specific request; they respond to
the client with a GNS reply. The GNS reply points the client to a specific
server to contact for the resource it requested. If none of the servers receiv-
ing the client's GNS request have or know of another server that has the
requested service, they simply don't respond, which leaves the requesting
client without the ability to access the requested resource.
servers. This doesn't mean they
GNS reply to a client can come from a local NetWare server or a Cisco
router, and generally, if there are local NetWare servers present, they should
respond to the client's request.
client's GNS. This saves the client from having to wait for remote NetWare
servers to respond. A second advantage of this arrangement is that precious
WAN bandwidth isn't occupied with GNS conversations between clients on
a segment with no local NetWare server and remote NetWare servers, as
shown in Figure 8.2.
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.