IPX Routing
Novell IPX also uses RIP for routing purposes. Although it is similarly named to the IP equivalent, it uses a different protocol. IPX RIP broadcasts datagrams out onto the network every sixty seconds. Upon receipt of a RIP datagram, a router adds one to the hop count of each route advertised and broadcasts a RIP datagram to the other networks, with which it is connected.
The cost of a route in an IPX network is determined by the metric known as ticks. In a LAN only environment this is the hop count plus one, e.g. three hops or four ticks. For an internetwork connected via a WAN or ISDN links, the tick count is factored on the speed of the WAN link.
We saw above the common network numbering scheme employed for a bridged network. By employing routing, LAN A, LAN B and LAN C become three separate networks on a network. The network numbering must reflect that situation.
In a Novell IPX environment we could allocate IPX network numbers 00000111 to LAN A, 00000222 to LAN B and 00000333 to LAN C. Having configured
Routing IP and IPX A-11
the ports of the OfficeConnect Remote to accept this protocol, routing will now occur between the remote network servers and workstations but addressed by different network numbers.
It should be noted that NetWare 3.X and later, uses the concept of internal IPX addresses, which is somewhat similar to network addressing. The internal address refers to the internal network within that server allowing internal processes to communicate. These numbers must be unique for all servers right across the network. Although network servers may appeared wired correctly, and in other respects seem to be working correctly, duplicated internal IPX addresses will not allow correct operation.
NetWare has a hop count limitation imposed by the RIP. On an IPX network a data packet can cross a maximum of fifteen routers before being discarded.