How Ipx Routing Works; Ipx Packet Format - 3Com LANPLEX 2500 EXTENDEDPLEX®2500 EXTENDED User Manual

6-4 C 6: R
HAPTER OUTING WITH
How IPX Routing
Works

IPX Packet Format

IPX
A router operates at the network layer of the OSI Reference Model. This
means that it receives its instructions to route packets from one segment to
another from a network-layer protocol. IPX, with the help of RIP, performs
these network layer tasks. These tasks include addressing, routing, and
switching information packets to move single packets from one location to
another. This section first describes the information included in an IPX
packet that helps it get delivered and then it describes the IPX packet
delivery process.
The IPX packet format consists of two parts: a 30-byte header and a data
portion. The network, node, and socket address for both the destination and
source are held within the packet's IPX header.
Figure 6-2 shows the IPX packet format.
Checksum (2 bytes)
Packet Length (2 bytes)
Transport Control Packet Type
(1 byte) (1 byte)
Destination Network (4 bytes)
Destination Node
(6 bytes)
Destination Socket
(2 bytes)
Source Network
(4 bytes)
Source Node
(6 bytes)
Source Socket
(2 bytes)
Upper-layer Data
Figure 6-2 IPX Packet Format