User`s guide

Configuring IPX Routing
How the Pipeline performs IPX routing
4-2 Preliminary January 30, 1998 Pipeline User’s Guide
interoperable with other vendors’ products that conform to these protocols and
associated RFCs.
Note:
IPX can be transmitted using different frame types. The Pipeline routes
only one IPX frame type, and it routes and spoofs IPX packets only if they are
encapsulated in that type of frame. If bridging is enabled in the same Connection
profile as IPX routing, the Pipeline will bridge any other IPX-packet frame types.
(For more information see Chapter 5, “Configuring the Pipeline as a Bridge.”)
Unlike an IP routing configuration, where the Pipeline uniquely identifies the
calling device by its IP address, an IPX routing configuration does not include a
built-in way to uniquely identify callers. For that reason, password authentication
is required unless IP routing is configured in the same Connection profile. (For
details, see Chapter 7, “Setting Up Pipeline Security.”)
IPX Service Advertising Protocol (SAP) tables
The Pipeline follows standard IPX SAP behavior for routers. However, when the
connection is to another Pipeline configured for IPX routing, both ends of the
connection exchange their entire SAP tables, so all remote services are
immediately added to each unit’s SAP table.
NetWare servers broadcast SAP packets every 60 seconds to make sure that
routers know about their services. Routers build a SAP table with an entry for
each service advertised by each known server. When a router stops receiving SAP
broadcasts from a server, it ages the SAP-table entry and eventually removes it
from the table.
Routers use SAP tables to respond to client queries. When a NetWare client
sends a SAP request to locate a service, the Pipeline consults its SAP table and
replies with its own hardware address and the internal address of the requested
server (similar to “Enabling proxy mode in the Pipeline” on page 3-6).
The client can then transmit packets whose destination address is the internal
address of the server. When the Pipeline receives those packets, it consults its RIP
table. If it finds an entry for that destination address, it brings up the connection
or forwards the packet across the active connection.