Editing Internetwork Packet Exchange (section)

===Network number===

The network number allows to address (and communicate with) the IPX nodes which do not belong to the same network or ''cabling system''. The '''cabling system''' is a network in which a [[data link layer]] protocol can be used for communication. To allow communication between different networks, they must be connected with IPX [[Router (computing)|routers]]. A set of interconnected networks is called an '''internetwork'''. Any [[Novell NetWare]] server may serve as an IPX router. Novell also supplied stand-alone routers. Other vendors ' multiprotocol routers often support IPX routing. Using different [[#Frame Formats|frame formats]] in one cabling system is possible, but it works similarly as if separate cabling systems were used (i.e. different network numbers must be used for different frame formats even in the same cabling system and a router must be used to allow communication between nodes using different frame formats in the same cabling system).

* Logical networks are assigned a unique 32-bit address in the range 0x1 to 0xFFFFFFFE ([[hexadecimal]]).
* Hosts have a 48-bit node address, which is by default set to the 6 bytes of the network interface card [[MAC address]]. Network addresses, which exist in addition to the node address but are not part of the MAC layer, are assigned only if an IPX router is present or by manual configuration in the network. The network address covers every network participant that can talk to another participant without the aid of an IPX router. In combination, both network and node address form an 80-bit unique identifier for each IPX node across connected logical networks. The node number itself is unique to the logical network only.
* Network number 00:00:00:00 refers to the current network, and is also used during router discovery. It's also the default in case no router is present, but can be changed by manual configuration, depending on the IPX implementation.
* Broadcast network number is FF:FF:FF:FF.