Verilink 9000 Series (34-00271) Product Manual - Manual (Page 337)

Summary of IPX Features 315
Novell has reserved several socket numbers for specific purposes. These are shown
in Table 19-1. Because socket numbers are internal to each node, several
workstations can use the same socket number at one time without any fear of
confusion.
RIP IPX Support
Details
The Routing Information Protocol (RIP) facilitates the exchange of routing
information on a NetWare internetwork. Like IPX, the RIP protocol is derived
from XNS. However, an extra field, Number of Ticks, was added to the packet
structure to improve the decision criteria for selecting the fastest route to a
destination. This change prohibits the straight integration of NetWare's RIP with
strictly conforming XNS implementations.
RIP broadcasts
The broadcast of RIP packets allows:
✦ workstations to locate the fastest route to a network number.
✦ routers to request routing information from other routers to update their own
internal tables.
✦ routers to respond to route requests from workstations and other routers.
✦ routers to ensure that all other routers are aware of the internetwork configuration.
✦ routers to detect a change in the internetwork configuration.
SAP IPX Support
Details
The Service Advertising Protocol (SAP) allows service-providing nodes, such as
file servers, print servers, gateway servers, and application servers, to advertise
their services and addresses. SAP makes the process of adding and removing
services on an internetwork dynamic. As servers are booted up, they advertise their
services using SAP; when they are brought down, they use SAP to indicate that
their services are no longer available.
SAP broadcasts
Through SAP, clients on the network can determine what services are available on
the network and obtain the internetwork address of the nodes (servers) where they
can access those services. This is an important function, because a workstation
cannot initiate a session with a service provider without first having that server's
address.
Table 19-1 Socket Numbers Used in the NetWare Environment
Socket number
(hexadecimal)
Description
451 NetWare Core Protocol
452 Service Advertising Protocol
453 Routing Information Protocol
455 NetBIOS
456 Diagnostics
4000 to 6000 Ephemeral sockets; used for interaction with file
servers and other network communications