Novell® Internet Access Server 4.1 includes source route bridging software that enables you to link token ring networks and create an extended network. This functionality is compatible with the source route bridging mechanism used by IBM to handle the flow of data between token ring networks. Source route bridging allows end stations to discover routes dynamically and determine which one to use when sending data to a destination.
Novell Internet Access Server 4.1 supports concurrent routing and bridging of all major protocols. Novell Internet Access Server 4.1 can be configured to route or bridge the TCP/IP, AppleTalk, and Internetwork Packet ExchangeTM (IPXTM ) protocols, and to bridge unroutable protocols such as IBM's NetBIOS and SNA. Because you cannot bridge and route the same protocol on the same interface, Novell Internet Access Server 4.1 also provides a mechanism for automatically disabling bridging when routing is enabled.
Novell Internet Access Server 4.1 can also bridge over Point-to-Point Protocol (PPP), frame relay, and X.25 wide area telecommunications links. Multiple WAN links can be used to connect multiple remote sites or to create backup links between two locations, providing fault tolerance if one link fails.
The use of source route bridging prevents packets sent between end stations on the same ring from passing on to other connected rings. This prevents extraneous traffic across networks, increasing the available bandwidth on all networks. Performance can be further enhanced by limiting traffic through the use of custom filters that permit packets from certain stations to pass while blocking packets from others. Filters can also increase network security by not allowing users on one ring to access another ring that contains sensitive information.
As token ring networks have grown, they have become increasingly difficult to manage; the Novell source route bridge software supports the bridging Management Information Base (MIB) defined in RFC 1286. The standards-based Simple Network Management Protocol (SNMP) allows organizations to install equipment from multiple vendors and manage the entire network from one centralized monitoring console. Novell Internet Access Server 4.1 supports the SNMP MIB variables as defined in RFC 1219, which can be managed using the Novell ManageWise® product or any other SNMP-based management console. When configured as a two-port local bridge, it can also be managed by IBM LAN Manager or IBM LAN Network Manager (which are different versions of the same product, both abbreviated as LNM).