IPX/SPX • Novell Internetwork Packet Exchange (IPX) has been around since 1980’s. • Novell Netware was the most popular network operating system in 1980’s. • Currently, Novell uses TCP/IP as default network protocol. • Why should we learn about IPX/SPX?
IPX/SPX Protocol Stack • Internetwork Packet Exchange (IPX) • Connectionless, predominantly layer 3 protocol • Responsible for finding the best path through a multipath IPX network • Sequenced Packet Exchange (SPX) • Connection-oriented layer 4 protocol • Provides guaranteed delivery services for the connectionless IPX • Service Advertisement Protocol (SAP) • Operates at layers 5, 6, and 7 • Advertises services running on IPX/SPX servers
IPX/SPX Protocol Stack • NetWare Core Protocol (NCP) • Functions at layers 4, 5, 6, and 7 of the OSI model • Facilitates client/server interaction on a NetWare network • Routing Information Protocol (RIP) • Distance-vector protocol built into the IPX/SPX protocol stack • Operates at layer 3 • Uses ticks and hop counts as metrics • NetWare Link Services Protocol (NLSP) • Link state routing protocol designed by Novell • Functions at layer 3
IPX/SPX Addressing • 80-bit (10 bytes) addresses consisting of a 32-bit (4 bytes) network portion and a 48-bit node portion • The network administrator arbitrarily assigns the network portion • No subnetting! No address classes! • MAC address of the node makes up the node portion of the address • Addresses normally appear in hexadecimal format • 0000.7C80.0000.8609.33e9 • What is good about using MAC addresses?
Communication • Client-Server • Novell Netware follows a strict client-server model. • Every Netware server builds a service advertisement table comprising all the network resources that it is aware of. • Clients use Get Nearest Server (GNS) request to locate servers. • Server-Server • Servers use SAP and RIP.
Service Advertisement Protocol (SAP) SAP advertisements on an IPX/SPX network allow servers to “advertise” running services to network clients NetWare servers take SAP broadcasts and build SAP tables.