Table Of Contents
Assigning Network Numbers to Individual Interfaces
Assigning Network Numbers to Individual Interfaces Task List
Assigning Network Numbers to Interfaces That Support a Single Network
Assigning Network Numbers to Interfaces That Support Multiple Networks
Enabling Concurrent Routing and Bridging
Configuring Integrated Routing and Bridging
Configuring IPX Enhanced IGRP Task List
Customizing Link Characteristics
Configuring the Percentage of Link Bandwidth Used by Enhanced IGRP
Adjusting the Interval Between Hello Packets and the Hold Time
Customizing the Exchange of Routing and Service Information
Redistributing Routing Information
Controlling the Advertising of Routes in Routing Updates
Controlling the Processing of Routing Updates
Controlling the Advertising of Services in SAP Updates
Controlling the Processing of SAP Updates
Understanding Level 1, 2, and 3 Routers
Configuring NLSP on an Interface
Configuring NLSP on a LAN Interface
Configuring NLSP on a WAN Interface
Customizing Link Characteristics
Enabling NLSP Multicast Addressing
Configuring the Link Delay and Throughput
Configuring the Maximum Hop Count
Specifying a Designated Router
Configuring Transmission and Retransmission Intervals
Limiting Partial Route Calculations
Understanding Area Addresses, Route Summaries, and Aggregated Routes
Understanding Route Redistribution
Understanding Route Summarization
Understanding Service and Path Selection
Configuring Route Aggregation Task List
Configuring Route Aggregation for Multiple NLSP Version 1.1 Areas
Configuring Route Aggregation for NLSP Version 1.1 and NLSP Version 1.0 Areas
Configuring Route Aggregation for Enhanced IGRP and NLSP Version 1.1 Environments
Configuring Route Aggregation for RIP and NLSP Version 1.1 Environments
Configuring Route Aggregation Using Named Access Lists
Customizing the Exchange of Routing Information
Configuring RIP and SAP Compatibility
Redistributing Routing Information
Configuring Next Hop Resolution Protocol
Configuring a Station with Static IPX-to-NBMA Address Mapping
Statically Configuring a Next Hop Server
Configuring NHRP Authentication
Triggering NHRP on a per-Destination Basis
Suppressing Forward and Reverse Record Options
Specifying the NHRP Responder Address
Changing the Time Period NBMA Addresses Are Advertised as Valid
Configuring IPX and SPX over WANs
Configuring SPX Spoofing over DDR
Configuring IPX Header Compression
Configuring the IPXWAN Protocol
Controlling Access to IPX Networks
Controlling Access to IPX Networks Task List
Creating Access Lists Using Numbers
Creating Access Lists Using Names
Applying Time Ranges to Access Lists
Creating Filters for Updating the Routing Table
Creating Broadcast Message Filters
Tuning IPX Network Performance
Controlling Novell IPX Compliance
Controlling the Forwarding of Type 20 Packets
Achieving Full Novell Compliance
Adjusting RIP and SAP Information
Controlling Responses to RIP Requests
Configuring RIP Update Packet Size
Configuring Static SAP Table Entries
Configuring the Queue Length for SAP Requests
Configuring SAP Update Packet Size
Disabling Sending of General RIP or SAP Queries
Controlling Responses to GNS Requests
Enabling Round-Robin Load Sharing
Enabling per-Host Load Sharing
Specifying the Use of Broadcast Messages
Using Helper Addresses to Forward Broadcast Packets
Enabling Fast Switching of IPX Directed Broadcast Packets
Controlling Route Cache Invalidation
Disabling Network Number -2 as the Default Route
Advertising Only Default RIP Routes
Configuring IPX Multilayer Switching
Monitoring and Maintaining the IPX Network
General Monitoring and Maintaining Tasks
Monitoring and Maintaining Caches, Tables, Interfaces, and Statistics
Specifying the Type and Use of Ping Packets
Troubleshooting Network Connectivity
Monitoring and Maintaining IPX Enhanced IGRP
Logging Enhanced IGRP Neighbor Adjacency Changes
Monitoring and Maintaining NLSP
Logging Adjacency State Changes
Monitoring and Maintaining NHRP
Monitoring and Maintaining IPX Accounting
Configuring Novell IPX
This chapter describes how to configure Novell Internetwork Packet Exchange (IPX) and provides configuration examples. For a complete description of the IPX commands in this chapter, refer to the "Novell IPX Commands" chapter in the Cisco IOS AppleTalk and Novell IPX Command Reference publication. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
IPX Addresses
An IPX network address consists of a network number and a node number expressed in the format network.node.
Network Numbers
The network number identifies a physical network. It is a 4-byte (32-bit) quantity that must be unique throughout the entire IPX internetwork. The network number is expressed as hexadecimal digits. The maximum number of digits allowed is eight.
The Cisco IOS software does not require that you enter all eight digits; you can omit leading zeros.
Node Numbers
The node number identifies a node on the network. It is a 48-bit quantity, represented by dotted triplets of four-digit hexadecimal numbers.
If you do not specify a node number for a router to be used on WAN links, the Cisco IOS software uses the hardware MAC address currently assigned to it as its node address. This is the MAC address of the first Ethernet, Token Ring, or FDDI interface card. If there are no valid IEEE interfaces, then the Cisco IOS software randomly assigns a node number using a number that is based on the system clock.
IPX Address Example
The following example shows how to configure an IPX network address:
4a.0000.0c00.23feIn this example, the network number is 4a (more specifically, it is 0000004a), and the node number is 0000.0c00.23fe. All digits in the address are hexadecimal.
IPX Configuration Task List
To configure IPX routing, perform the tasks in the following sections:
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Configuring IPX Routing (Required)
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See the "Novell IPX Configuration Examples" section at the end of this chapter for configuration examples.
Configuring IPX Routing
You configure IPX routing by first enabling it on the router and then configuring it on each interface.
Optionally, you can route IPX on some interfaces and transparently bridge it on other interfaces. You can also route IPX traffic between routed interfaces and bridge groups, or route IPX traffic between bridge groups.
To configure IPX routing, perform the tasks in the following sections. The first two tasks are required; the rest are optional.
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IPX Default Routes
In IPX, a default route is the network where all packets for which the route to the destination address is unknown are forwarded.
Original Routing Information Protocol (RIP) implementations allowed the use of network -2 (0xFFFFFFFE) as a regular network number in a network. With the inception of NetWare Link Services Protocol (NLSP), network -2 is reserved as the default route for NLSP and RIP. Both NLSP and RIP routers should treat network -2 as a default route. Therefore, you should implement network -2 as the default route regardless of whether you configure NLSP in your IPX network.
By default, Cisco IOS software treats network -2 as the default route. You should ensure that your IPX network does not use network -2 as a regular network. If, for some reason, you must use network -2 as a regular network, you can disable the default behavior. To do so, see the "Adjusting Default Routes" section later in this chapter.
For more background information on how to handle IPX default routes, refer to the Novell NetWare Link Services Protocol (NLSP) Specification, Revision 1.1 publication.
Enabling IPX Routing
The first step in enabling IPX routing is to enable it on the router. If you do not specify the node number of the router to be used on WAN links, the Cisco IOS software uses the hardware MAC address currently assigned to it as its node address. This is the MAC address of the first Ethernet, Token Ring, or FDDI interface card. If there are no valid IEEE interfaces, then the Cisco IOS software randomly assigns a node number using a number that is based on the system clock.
To enable IPX routing, use the following command in global configuration mode:
For an example of how to enable IPX routing, see the "IPX Routing Examples" section at the end of this chapter.
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Assigning Network Numbers to Individual Interfaces
After you have enabled IPX routing, you enable IPX routing on the individual interfaces by assigning network numbers to those interfaces.
You enable IPX routing on interfaces that support a single network or multiple networks.
When you enable IPX routing on an interface, you can also specify an encapsulation (frame type) to use for packets being sent on that network. Table 8 lists the encapsulation types you can use on IEEE interfaces and shows the correspondence between Cisco naming conventions and Novell naming conventions for the encapsulation types.
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Assigning Network Numbers to Individual Interfaces Task List
The following sections describe how to enable IPX routing on interfaces that support a single network and on those that support multiple networks. You must perform one of the tasks to enable IPX routing on an interface:
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Assigning Network Numbers to Interfaces That Support a Single Network
A single interface can support a single network or multiple logical networks. For a single network, you can configure any encapsulation type. Of course, it should match the encapsulation type of the servers and clients using that network number.
To assign a network number to an interface that supports a single network, use the following command in interface configuration mode:
ipx network network [encapsulation encapsulation-type]
Enable IPX routing on an interface.
If you specify an encapsulation type, be sure to choose the one that matches the one used by the servers and clients on that network. See Table 8 for a list of encapsulation types you can use on IEEE interfaces.
For an example of how to enable IPX routing, see the "IPX Routing Examples" section at the end of this chapter.
Assigning Network Numbers to Interfaces That Support Multiple Networks
When assigning network numbers to an interface that supports multiple networks, you must specify a different encapsulation type for each network. Because multiple networks share the physical medium, the Cisco IOS software is allowed to identify the packets that belong to each network. For example, you can configure up to four IPX networks on a single Ethernet cable, because four encapsulation types are supported for Ethernet. Remember, the encapsulation type should match the servers and clients using the same network number. See Table 8 for a list of encapsulation types you can use on IEEE interfaces.
There are two ways to assign network numbers to interfaces that support multiple networks. You can use subinterfaces or primary and secondary networks.
Subinterfaces
You typically use subinterfaces to assign network numbers to interfaces that support multiple networks.
A subinterface is a mechanism that allows a single physical interface to support multiple logical interfaces or networks. That is, several logical interfaces or networks can be associated with a single hardware interface. Each subinterface must use a distinct encapsulation, and the encapsulation must match that of the clients and servers using the same network number.
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Any interface configuration parameters that you specify on an individual subinterface are applied to that subinterface only.
To configure multiple IPX networks on a physical interface using subinterfaces, use the following commands beginning in global configuration mode:
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To configure more than one subinterface, repeat these two steps. See Table 8 for a list of encapsulation types you can use on IEEE interfaces.
For examples of configuring multiple IPX networks on an interface, see the "IPX Routing on Multiple Networks Examples" section at the end of this chapter.
Primary and Secondary Networks
When assigning network numbers to interfaces that support multiple networks, you can also configure primary and secondary networks.
The first logical network you configure on an interface is considered the primary network. Any additional networks are considered secondary networks. Again, each network on an interface must use a distinct encapsulation and it should match that of the clients and servers using the same network number.
Any interface configuration parameters that you specify on this interface are applied to all the logical networks. For example, if you set the routing update timer to 120 seconds, this value is used on all four networks.
To use primary and secondary networks to configure multiple IPX networks on an interface, use the following commands in interface configuration mode:
To configure more than one secondary network, repeat as appropriate. See Table 8 for a list of encapsulation types you can use on IEEE interfaces.
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Enabling Concurrent Routing and Bridging
You can route IPX on some interfaces and transparently bridge it on other interfaces simultaneously. To enable this type of routing, you must enable concurrent routing and bridging. To enable concurrent routing and bridging, use the following command in global configuration mode:
Configuring Integrated Routing and Bridging
Integrated routing and bridging (IRB) enables a user to route IPX traffic between routed interfaces and bridge groups, or route IPX traffic between bridge groups. Specifically, local or unroutable traffic is bridged among the bridged interfaces in the same bridge group. Routable traffic is routed to other routed interfaces or bridge groups. Using IRB, you can do the following:
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For more information about configuring integrated routing and bridging, refer to the "Configuring Transparent Bridging" chapter in the Cisco IOS Bridging and IBM Networking Configuration Guide.
Configuring IPX Enhanced IGRP
Enhanced IGRP is an enhanced version of the Interior Gateway Routing Protocol (IGRP) developed by Cisco. Enhanced IGRP uses the same distance vector algorithm and distance information as IGRP. However, the convergence properties and the operating efficiency of Enhanced IGRP have improved significantly over IGRP.
The convergence technology is based on research conducted at SRI International and employs an algorithm referred to as the Diffusing Update Algorithm (DUAL). This algorithm guarantees loop-free operation at every instant throughout a route computation, and allows all routers involved in a topology change to synchronize at the same time. Routers that are not affected by topology changes are not involved in recomputations. The convergence time with DUAL rivals that of any other existing routing protocol.
Enhanced IGRP Features
Enhanced IGRP offers the following features:
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Enhanced IGRP Components
Enhanced IGRP has four basic components discussed in the following sections:
Neighbor Discovery/Recovery
Neighbor discovery/recovery is the process that routers use to dynamically learn of other routers on their directly attached networks. Routers must also discover when their neighbors become unreachable or inoperative. The router achieves neighbor discovery/recovery with low overhead by periodically sending small hello packets. As long as hello packets are received, a router can determine that a neighbor is alive and functioning. Once this status is determined, the neighboring devices can exchange routing information.
Reliable Transport Protocol
The reliable transport protocol is responsible for guaranteed, ordered delivery of Enhanced IGRP packets to all neighbors. It supports intermixed transmission of multicast and unicast packets. Some Enhanced IGRP packets must be sent reliably, and others need not be. For efficiency, reliability is provided only when necessary. For example, on a multiaccess network that has multicast capabilities (such as Ethernet) it is not necessary to send hellos reliably to all neighbors individually. Therefore, Enhanced IGRP sends a single multicast hello with an indication in the packet informing the receivers that the packet need not be acknowledged. Other types of packets (such as updates) require acknowledgment, which is indicated in the packet. The reliable transport has a provision to send multicast packets quickly when there are unacknowledged packets pending. This provision helps ensure that convergence time remains low in the presence of varying speed links.
DUAL Finite-State Machine
The DUAL finite-state machine embodies the decision process for all route computations. It tracks all routes advertised by all neighbors. DUAL uses the distance information (known as a metric) to select efficient, loop-free paths. DUAL selects routes to be inserted into a routing table based on feasible successors. A successor is a neighboring router used for packet forwarding that has a least-cost path to a destination that is guaranteed not to be part of a routing loop. When there are no feasible successors but there are neighbors advertising the destination, a recomputation must occur. This is the process whereby a new successor is determined. The amount of time it takes to recompute the route affects the convergence time. Recomputation is processor-intensive. It is advantageous to avoid recomputation if it is not necessary. When a topology change occurs, DUAL will test for feasible successors. If there are feasible successors, it will use any it finds in order to avoid unnecessary recomputation.
Protocol-Dependent Modules
The protocol-dependent modules are responsible for network layer protocol-specific tasks. They are also responsible for parsing Enhanced IGRP packets and informing DUAL of the new information received. Enhanced IGRP asks DUAL to make routing decisions, but the results are stored in the IPX routing table. Also, Enhanced IGRP is responsible for redistributing routes learned by other IPX routing protocols.
Configuring IPX Enhanced IGRP Task List
To enable IPX Enhanced IGRP, perform the tasks in the following sections. Only the first task is required; the remaining tasks are optional.
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Enabling IPX Enhanced IGRP
To create an IPX Enhanced IGRP routing process, use the following commands beginning in global configuration mode:
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ipx router eigrp autonomous-system-number
Enable an Enhanced IGRP routing process.
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network {network-number | all}
Enable Enhanced IGRP on a network.
To associate multiple networks with an Enhanced IGRP routing process, you can repeat the preceding two steps.
For an example of how to enable Enhanced IGRP, see the "IPX Enhanced IGRP Example" section at the end of this chapter.
Customizing Link Characteristics
You might want to customize the Enhanced IGRP link characteristics. The following sections describe these customization tasks:
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Configuring the Percentage of Link Bandwidth Used by Enhanced IGRP
By default, Enhanced IGRP packets consume a maximum of 50 percent of the link bandwidth, as configured with the bandwidth interface subcommand. If a different value is desired, use the ipx bandwidth-percent command. This command may be useful if a different level of link utilization is required, or if the configured bandwidth does not match the actual link bandwidth (it may have been configured to influence route metric calculations).
To configure the percentage of bandwidth that may be used by Enhanced IGRP on an interface, use the following command in interface configuration mode:
ipx bandwidth-percent eigrp as-number percent
Configure the percentage of bandwidth that may be used by Enhanced IGRP on an interface.
For an example of how to configure the percentage of Enhanced IGRP bandwidth, see the "IPX Enhanced IGRP Bandwidth Configuration Example" section at the end of this chapter.
Configuring Maximum Hop Count
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By default, IPX packets whose hop count exceeds 15 are discarded. In larger internetworks, this maximum hop count may be insufficient. You can increase the hop count to a maximum of 254 hops for Enhanced IGRP. To modify the maximum hop count, use the following command in global configuration mode:
Adjusting the Interval Between Hello Packets and the Hold Time
You can adjust the interval between hello packets and the hold time.
Routers periodically send hello packets to each other to dynamically learn of other devices on their directly attached networks. Routers use this information to discover their neighbors and to discover when their neighbors become unreachable or inoperative.
By default, hello packets are sent every 5 seconds. The exception is on low-speed, nonbroadcast multiaccess (NBMA) media, where the default hello interval is 60 seconds. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command. The default hello interval remains 5 seconds for high-speed NBMA networks.
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You can configure the hold time on a specified interface for a particular Enhanced IGRP routing process designated by the autonomous system number. The hold time is advertised in hello packets and indicates to neighbors the length of time they should consider the sender valid. The default hold time is three times the hello interval, or 15 seconds.
On very congested and large networks, 15 seconds may not be sufficient time for all routers to receive hello packets from their neighbors. In this case, you may want to increase the hold time. To increase the hold time, use the following command in interface configuration mode:
To change the interval between hello packets, use the following command in interface configuration mode:
ipx hello-interval eigrp autonomous-system-number seconds
Set the interval between hello packets.
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Customizing the Exchange of Routing and Service Information
You might want to customize the exchange of routing and service information. The following sections describe these customization tasks:
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Redistributing Routing Information
By default, the Cisco IOS software redistributes IPX RIP routes into Enhanced IGRP, and vice versa.
To disable route redistribution, use the following command in IPX-router configuration mode:
no redistribute {connected | eigrp autonomous-system-number | rip | static}
Disable redistribution of RIP routes into Enhanced IGRP and Enhanced IGRP routes into RIP.
The Cisco IOS software does not automatically redistribute NLSP routes into Enhanced IGRP routes and vice versa. To configure this type of redistribution, use the following commands beginning in global configuration mode:
For an example of how to enable redistribution of Enhanced IGRP and NLSP, see the "Enhanced IGRP and NLSP Route Redistribution Example" section at the end of this chapter.
Disabling Split Horizon
Split horizon controls the sending of Enhanced IGRP update and query packets. If split horizon is enabled on an interface, these packets are not sent for destinations if this interface is the next hop to that destination.
By default, split horizon is enabled on all interfaces.
Split horizon blocks information about routes from being advertised by the Cisco IOS software out any interface from which that information originated. This behavior usually optimizes communication among multiple routers, particularly when links are broken. However, with nonbroadcast networks (such as Frame Relay and SMDS), situations can arise for which this behavior is less than ideal. For these situations, you can disable split horizon.
To disable split horizon, use the following command in interface configuration mode:
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Controlling the Advertising of Routes in Routing Updates
To control which devices learn about routes, you can control the advertising of routes in routing updates. To control this advertising, use the following command in router configuration mode:
distribute-list access-list-number out [interface-name |
routing-process]Control the advertising of routes in routing updates.
Controlling the Processing of Routing Updates
To control the processing of routes listed in incoming updates, use the following command in router configuration mode:
distribute-list access-list-number in [interface-name]
Control which incoming route updates are processed.
Controlling SAP Updates
If IPX Enhanced IGRP peers are found on an interface, you can configure the Cisco IOS software to send SAP updates either periodically or when a change occurs in the SAP table. When no IPX Enhanced IGRP peer is present on the interface, periodic SAPs are always sent.
On serial lines, by default, if an Enhanced IGRP neighbor is present, the Cisco IOS software sends SAP updates only when the SAP table changes. On Ethernet, Token Ring, and FDDI interfaces, by default, the software sends SAP updates periodically. To reduce the amount of bandwidth required to send SAP updates, you might want to disable the periodic sending of SAP updates on LAN interfaces. This feature should only be disabled when all nodes out of this interface are Enhanced IGRP peers; otherwise, loss of SAP information on the other nodes will result.
To send SAP updates only when a change occurs in the SAP table, use the following command in interface configuration mode:
ipx sap-incremental eigrp autonomous-system-number
Send SAP updates only when a change in the SAP table occurs, and send only the SAP changes.
To send SAP updates only when a change occurs in the SAP table and to send only the SAP changes, use the following command in interface configuration mode:
ipx sap-incremental eigrp autonomous-system-number rsup-only
Send SAP updates only when a change in the SAP table occurs, and send only the SAP changes.
When you enable incremental SAP using the ipx sap-incremental eigrp rsup-only command, Cisco IOS software disables the exchange of route information via Enhanced IGRP for that interface.
To send periodic SAP updates, use the following command in interface configuration mode:
no ipx sap-incremental eigrp autonomous-system-number
Send SAP updates periodically.
For an example of how to configure SAP updates, see the "Enhanced IGRP SAP Update Examples" section at the end of this chapter.
To disable split horizon for incremental SAP, use the following command in interface configuration mode:
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Controlling the Advertising of Services in SAP Updates
To control which devices learn about services, you can control the advertising of these services in SAP updates. To control this advertising, use the following command in router configuration mode:
distribute-sap-list access-list-number out [interface-name | routing-process]
Control the advertising of services in SAP updates distributed between routing processes.
For a configuration example of controlling the advertisement of SAP updates, see the "Advertisement and Processing of SAP Update Examples" section at the end of this chapter.
Controlling the Processing of SAP Updates
To control the processing of routes listed in incoming updates, use the following command in router configuration mode:
distribute-sap-list access-list-number in [interface-name]
Control which incoming SAP updates are processed.
For a configuration example of controlling the processing of SAP updates, see the "Advertisement and Processing of SAP Update Examples" section at the end of this chapter.
Querying the Backup Server
The backup server table is a table kept for each Enhanced IGRP peer. It lists the IPX servers that have been advertised by that peer. If a server is removed from the main server table at any time and for any reason, the Cisco IOS software examines the backup server table to learn if this just-removed server is known by any of the Enhanced IGRP peers. If it is, the information from that peer is advertised back into the main server table just as if that peer had readvertised the server information to this router. Using this method to allow the router to keep the backup server table consistent with what is advertised by each peer means that only changes to the table must be advertised between Enhanced IGRP routers; full periodic updates need not be sent.
By default, the Cisco IOS software queries its own copy of the backup server table of each Enhanced IGRP neighbor every 60 seconds. To change this interval, use the following command in global configuration mode:
ipx backup-server-query-interval interval
Specify the minimum period of time between successive queries of the backup server table of a neighbor.
Configuring NLSP
NLSP is a link-state routing protocol based on the Open System Interconnection (OSI) Intermediate System-to-Intermediate System (IS-IS) protocol.
NLSP is designed to be used in a hierarchical routing environment, in which networked systems are grouped into routing areas. Routing areas can then be grouped into routing domains, and domains can be grouped into an internetwork.
Understanding Level 1, 2, and 3 Routers
Level 1 routers connect networked systems within a given routing area. Areas are connected to each other by Level 2 routers, and domains are connected by Level 3 routers. A Level 2 router also acts as a Level 1 router within its own area; likewise, a Level 3 router also acts as a Level 2 router within its own domain.
The router at each level of the topology stores complete information for its level. For instance, Level 1 routers store complete link-state information about their entire area. This information includes a record of all the routers in the area, the links connecting them, the operational status of the devices and their links, and other related parameters. For each point-to-point link, the database records the end-point devices and the state of the link. For each LAN, the database records which routers are connected to the LAN. Similarly, Level 2 routers would store information about all the areas in the routing domain, and Level 3 routers would store information about all the domains in the internetwork.
Although NLSP is designed for hierarchical routing environments containing Level 1, 2, and 3 routers, only Level 1 routing with area route aggregation and route redistribution has been defined in a specification.
Understanding NLSP Databases
NLSP is a link-state protocol, which means that every router in a routing area maintains an identical copy of the link-state database. This database contains all information about the topology of the area. All routers synchronize their views of the databases among themselves to keep their copies of the link-state databases consistent. NLSP has the following three major databases:
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Cisco Support of NLSP
The Cisco implementation of NLSP supports the Novell NLSP specification, version 1.1. Our implementation of NLSP also includes read-only NLSP MIB variables.
Configuring NLSP Task List
To configure NLSP, you must have configured IPX routing on your router, as described previously in this chapter. Then, you must perform the tasks described in the following sections:
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You can optionally perform the tasks described in the following sections:
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For an example of enabling NLSP, see the "IPX Routing Protocols Examples" section at the end of this chapter.
Defining an Internal Network
An internal network number is an IPX network number assigned to the router. For NLSP to operate, you must configure an internal network number for each device.
To enable IPX routing and to define an internal network number, use the following commands in global configuration mode:
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ipx routing
Enable IPX routing.
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ipx internal-network network-number
Define an internal network number.
Enabling NLSP Routing
To enable NLSP, use the following commands beginning in global configuration mode:
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ipx router nlsp [tag]
Enable NLSP.
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area-address address mask
Define a set of network numbers to be part of the current NLSP area.
Configuring NLSP on an Interface
You configure NLSP differently on LAN and WAN interfaces, as described in the following sections:
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Configuring NLSP on a LAN Interface
To configure NLSP on a LAN interface, use the following commands in interface configuration mode:
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ipx network network [encapsulation encapsulation-type]
Enable IPX routing on an interface.
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ipx nlsp [tag] enable
Enable NLSP on the interface.
To configure multiple encapsulations on the same physical LAN interfaces, you must configure subinterfaces. Each subinterface must have a different encapsulation type. To configure subinterfaces, use the following commands beginning in global configuration mode:
Repeat these three steps for each subinterface.
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Configuring NLSP on a WAN Interface
To configure NLSP on a WAN interface, use the following commands beginning in global configuration mode:
Customizing Link Characteristics
You might want to customize the NLSP link characteristics. The following sections describe these customization tasks:
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Enabling NLSP Multicast Addressing
Cisco IOS supports the use of NLSP multicast addressing for Ethernet, Token Ring, and FDDI router interfaces. This capability is only possible when the underlying Cisco hardware device or driver supports multicast addressing.
With this feature, the router defaults to using multicasts on Ethernet, Token Ring, and FDDI interfaces, instead of broadcasts, to address all NLSP routers on the network. If an adjacent neighbor does not support NLSP multicasting, the router will revert to using broadcasts on the affected interface.
This feature is only available on routers running Cisco IOS software Release 11.3 or later. When routers running prior versions of Cisco IOS software are present on the same network with routers running Cisco IOS Release 11.3 software, broadcasts will be used on any segment shared by the two routers.
The NLSP multicast addressing offers the following benefits:
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Enabling NLSP Multicast Addressing Task List
The following sections describe configuration tasks associated with the NLSP multicast addressing:
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Enabling NLSP Multicast Addressing
By default, NLSP multicast addressing is enabled. You need not configure anything to turn on NLSP multicasting.
Disabling NLSP Multicast Addressing
Typically, you do not want to substitute broadcast addressing where NLSP multicast addressing is available. NLSP multicast addressing uses network bandwidth more efficiently than broadcast addressing. However, there are circumstances where you might want to disable NLSP multicast addressing.
For example, you might want to disable NLSP multicast addressing in favor of broadcast addressing when one or more devices on a segment do not support NLSP multicast addressing. You might also want to disable it for testing purposes.
If you want to disable NLSP multicast addressing, you can do so for the entire router or for a particular interface.
To disable multicast addressing for the entire router, use the following commands in IPX-router configuration mode:
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ipx router nlsp
Enter NLSP router configuration mode.
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no multicast
Disable NLSP multicast addressing on the router.
To disable multicast addressing on a particular router interface, use the following command in interface configuration mode:
For examples of how to disable NLSP multicast addressing, see the "NLSP Multicast Addressing Examples" section at the end of this chapter.
Configuring the Metric Value
NLSP assigns a default link cost (metric) based on the link throughput. If desired, you can set the link cost manually.
Typically, you need not set the link cost manually; however, there are some cases where you might want to. For example, in highly redundant networks, you might want to favor one route over another for certain kinds of traffic. As another example, you might want to ensure load sharing. Changing the metric value can help achieve these design goals.
To set the NLSP link cost for an interface, use the following command in interface configuration mode:
Configuring the Link Delay and Throughput
The delay and throughput of each link are used by NLSP as part of its route calculations. By default, these parameters are set to appropriate values or, in the case of IPXWAN, are dynamically measured.
Typically, you need not change the link delay and throughput; however, there are some cases where you might want to change these parameters. For example, in highly redundant networks, you might want to favor one route over another for certain kinds of traffic. To favor one route over another, you would change the metric on the less-desirable path to be slightly worse by assigning it a higher metric value using the ipx-link-delay command. In this case, traffic is forced to route over the favorable path. As another example, you might want to ensure load sharing. To load share, you would ensure that the metrics on the equal paths are the same.
The link delay and throughput you specify replaces the default value or overrides the value measured by IPXWAN when it starts. The value is also supplied to NLSP for use in metric calculations.
To change the link delay, use the following command in interface configuration mode:
To change the throughput, use the following command in interface configuration mode:
Configuring the Maximum Hop Count
By default, IPX packets whose hop count exceeds 15 are discarded. In larger internetworks, this maximum hop count may be insufficient. You can increase the hop count to a maximum of 127 hops for NLSP.
For example, if you have a network with end nodes separated by more than 15 hops, you can set the maximum number of hops considered to be reachable by non-RIP routing protocols to a value from 16 to 127.
To modify the maximum hop count, use the following command in global configuration mode:
Specifying a Designated Router
Note
NLSP elects a designated router on each LAN interface. The designated router represents all routers that are connected to the same LAN segment. It creates a virtual router called a pseudonode, which generates routing information on behalf of the LAN and sends it to the remainder of the routing area. The routing information generated includes adjacencies and RIP routes. The use of a designated router substantially reduces the number of entries in the LSP database.
