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Novell developed NLSP to meet the demands of large IPX internetworks. As a link state routing protocol, NLSP offers better performance, reliability, and scalability than the IPX RIP routing traditionally employed by NetWare servers.
Unlike RIP and SAP, which periodically broadcast routing and service information respectively, NLSP transmits routing information only when a change occurs in a route or service somewhere in the network, or every two hours ---whichever occurs first. Because NLSP generates fewer routing updates than RIP and SAP, it uses less network bandwidth to maintain its routing database.
To transmit information about its directly connected routers and the links to those routers, an NLSP router uses Link State Packets (LSPs). By default, LSPs are 512 bytes, a nominal value that is sufficient for most IPX networks. If you have a large network---on the order of 4,000 routes and 2,000 services or more---you should increase the value of the LSP Size parameter to 1024. To configure this parameter, refer to How to Change the LSP Size.
By default, NLSP broadcasts its packets because some LAN drivers do not properly support multicast , a transmission mode that enables only those devices listening for a specific multicast packet address to accept the packet. You can, however, change the NLSP packet transmission mode to multicast with the MAC Channel parameter. An advantage of using multicast transmission is that NLSP packets sent by multicast do not clutter nonrouting nodes with unnecessary traffic.
NOTE: All NetWare systems on the same LAN must use the same NLSP packet transmission mode.
NLSP makes large IPX internetworks more manageable by allowing you to partition them into administrative domains called routing areas . Each routing area can be identified by up to three area addresses , a unique, 4-byte hexadecimal number that identifies each NLSP router as being part of a routing area. Although area addresses are not required, they are available chiefly for compatibility with future versions of NLSP and do provide some benefit for large IPX internetworks.
WARNING: Do not configure area addresses unless you must partition a large IPX internetwork. If you make an error in the address assignments, you can partition your network inadvertently and lose connectivity between some routers.
Each NLSP router is identified by a unique, 6-byte hexadecimal number called the system ID . The default system ID comprises a 2-byte constant, 0x0200, followed by the router's own internal network number. You should not change the system ID unless you have another numbering scheme in place with which you can reliably track and manage the NLSP routers on your network. If you must change a router's system ID, use another unique number, such as the physical address of one of the router's network interface boards.
Using a default cost value based on media throughput, NLSP chooses the best route by which to forward IPX packets. Novell Internet Access Server 4.1 enables you to override this value on an interface. By overriding the default cost, you can establish preferred routes, balance traffic loads among interfaces, and set up specific traffic flows between routers. For more information, refer to Balancing Traffic Loads over Equal-Cost Routes.
All NLSP routers have a configurable parameter called the Priority . The router with the highest priority becomes the Designated Router , which assumes the responsibility for exchanges of link state information on behalf of all other NLSP routers on the LAN. You do not typically need to change a router's Priority value; the NLSP routers automatically elect one from themselves. However, if you want to force a router to become the Designated Router for its LAN, increase its Priority value to at least 85. The router you choose should be typically up and should have enough memory to process NLSP routing information and generate the pseudonode LSP for its LAN. If you want to prevent a particular router from becoming the Designated Router, decrease its Priority value.
IMPORTANT: Novell Internet Access Server 4.1 provides a set of convergence parameters that enable you to customize the operation of NLSP on your router. The default values for these parameters are sufficient for most IPX networks and should be changed only on the advice of your technical support representative.
When configuring NLSP on an interface, you can set the NLSP State parameter to one of two states: On or Off . On enables the router to exchange NLSP packets freely with other NLSP routers on the attached network. Off disables NLSP routing on the interface.
This topic contains the following sections:
If you implement NLSP throughout a large IPX internetwork, or even if you want to configure NLSP on just a few routers or servers, refer to NLSP Migration for information about planning your implementation of NLSP.
To configure NLSP on the router, complete the following steps:
Load NIASCFG, then select the following parameter path:
Select Configure NIAS > Protocols and Routing > Protocols > IPX
Select the Routing Protocol parameter, then select NLSP with RIP/SAP Compatibility .
Press Esc to return to the Internetworking Configuration menu, then select the following path:
Select Bindings > a network interface > Expert Bind Options > NLSP Bind Options
Select NLSP State .
If you want to run NLSP over the interface, select On.
This enables NLSP routing on the interface.
If the interface is on an area boundary, or if you want to filter incoming RIP or SAP packets at the interface, select Off.
If the router supports two or more interfaces and you want to filter routes and services to a remote site through this interface:
To enable RIP and SAP, refer to Configuring RIP and SAP.
Select MAC Channel , then select the NLSP packet transmission mode.
If you select Multicast , NLSP automatically determines the multicast address. All systems on a network must be set to Multicast ; otherwise, the systems default to Broadcast , the default state for this parameter.
IMPORTANT: Make sure the driver you are using supports multicast transmission; drivers that do not support multicast can cause systems to become unaware of each other.
If you want to customize the interface further, configure one or more of the following parameters:
IMPORTANT: Because the default settings for these parameters are suitable for most NLSP networks, you should change them only for a specific purpose. Misconfiguring these parameters can increase routing traffic or cause loss of connectivity on your network.
Configure this parameter if you have a bridge or other device on your network, or if you want to transmit smaller packets over a WAN.
The default value for this parameter is 0, which means do not override the current pace.
Press Esc and save your changes.
Press Esc to return to the Internetworking Configuration menu.
If you want these changes to take effect immediately, select Reinitialize System .
If you want to configure other parameters, do so now, then reinitialize the system when you are finished.
The larger the packet a network can carry, the fewer LSPs are required to propagate an NLSP router's link state information on that network. However, the LSP used by the router must be no larger than the largest frame size supported by the network, less 30 bytes for the IPX header. For example, an ARCnet* LAN can transmit no more than 576 bytes at a time. If you leave LSP Size at the default value of 1024, the LSP cannot be transmitted across the LAN because it is too large. The result is that the network is prevented from converging.
Before you begin, you should know the maximum frame size supported by the network to which the NLSP router is connected.
To change the size of the LSP that a router transmits, complete the following steps:
Load NIASCFG, then select the following parameter path:
Select Configure NIAS > Protocols and Routing > Protocols > IPX > Expert Configuration Options
Select LSP Size , enter a value between 128 and 4096, then press Enter .
Press Esc and save your changes.
Press Esc to return to the Internetworking Configuration menu.
If you want this change to take effect immediately, select Reinitialize System .
If you want to configure other parameters, do so now, then reinitialize the system when you are finished.
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