Table of Contents

Configuring ATM Routing and PNNI

This chapter describes the Interim Interswitch Signaling Protocol (IISP) and Private Network-Network Interface (PNNI) ATM routing protocol implementations on the ATM switch router.

Note   This chapter provides advanced configuration instructions for the Catalyst 8540 MSR, Catalyst 8510 MSR, and LightStream 1010 ATM switch routers. For conceptual and background information, refer to the Guide to ATM Technology. For complete descriptions of the commands mentioned in this chapter, refer to the ATM Switch Router Command Reference publication.

This chapter includes the following sections:

Overview

To place calls between ATM end systems, signalling consults either IISP, a static routing protocol, or PNNI, a dynamic routing protocol. PNNI provides quality of service (QoS) routes to signalling based on the QoS requirements specified in the call setup request.

For detailed discussions of the following topics, refer to the Guide to ATM Technology:

ATM Addresses

The autoconfigured ATM address of the ATM switch router suffices when implementing single-level PNNI. Hierarchical PNNI requires an addressing scheme to ensure global uniqueness of the ATM address and to plan for future network expansion.

For detailed discussions of the following related topics, refer to the Guide to ATM Technology:

IISP Configuration

This section describes the procedures necessary for Interim Interswitch Signaling Protocol (IISP) configuration, and includes the following subsections:

Configuring the Routing Mode

The ATM routing software can be restricted to operate in static mode. In this mode, the call routing is restricted to only the static configuration of ATM routes, disabling operation of any dynamic ATM routing protocols, such as PNNI.

The atm routing-mode command is different from deleting all PNNI nodes using the node command and affects Integrated Local Management Interface (ILMI) autoconfiguration. If the switch is configured using static routing mode on each interface, the switch ILMI variable atmfAtmLayerNniSigVersion is set to IISP. This causes either of the following to happen:

To configure the routing mode, perform these steps, beginning in global configuration mode:

Example

The following example shows how to use the atm routing-mode static command to restrict the switch operation to static routing mode:

The following example shows how to reset the switch operation back to PNNI if the switch is operating in static mode:

Displaying the ATM Routing Mode Configuration

To display the ATM routing mode configuration, use the following privileged EXEC command:

Example

The following example shows the ATM routing mode configuration using the more system:running-config privileged EXEC command:

Configuring the ATM Address

If you are planning to implement only a flat topology network (and have no future plans to migrate to PNNI hierarchy), you can skip this section and use the preconfigured ATM address assigned by Cisco Systems.

Note   For information about ATM address considerations, see the "ATM Addresses" section 10-2.

To change the active ATM address, create a new address, verify that it exists, and then delete the current active address. Follow these steps, beginning in global configuration mode:

Example

The following example shows how to add the ATM address prefix 47.0091.8100.5670.000.0ca7.ce01. Using the ellipses (...) adds the default Media Access Control (MAC) address as the last six bytes.

Displaying the ATM Address Configuration

To display the ATM address configuration, use the following EXEC command:

Example

The following example shows the ATM address configuration using the show atm addresses EXEC command:

Configuring Static Routes

Use the atm route command to configure a static route. A static route attached to an interface allows all ATM addresses matching the configured address prefix to be reached through that interface.

Note   For private User-Network Interface (UNI) interfaces where ILMI address registration is not used, internal-type static routes should be configured to a 19-byte address prefix representing the attached end system.

To configure a static route, use the following global configuration command:

Examples

The following example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0/0:

The following example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0/0 configured with a scope 1 associated:

Displaying the Static Route Configuration

To display the ATM static route configuration, use the following EXEC command:

Examples

The following example shows the ATM static route configuration using the show atm route privileged EXEC command:

Configuring ATM Address Groups

ATM address groups allow more than one interface to have the same internal address prefix for the same static route. These multiple static routes provide load balancing for traffic from an end station.

Configure the interfaces in a group by performing the following tasks, beginning in global configuration mode:

Example

The following example shows how to configure ATM interface 1/1/0 and ATM interface 3/0/1 in ATM address group 5:

Displaying ATM Address Group Configuration

To determine if an interface is a member of an ATM address group, use the following privileged EXEC command:

Example

The following example shows the ATM address group configuration for ATM interface 1/1/0 and ATM interface 3/0/1:

Basic PNNI Configuration

This section describes all the procedures necessary for a basic PNNI configuration and includes the following subsections:

Configuring PNNI without Hierarchy

The ATM switch router defaults to a working PNNI configuration suitable for operation in isolated flat topology ATM networks. The switch comes with a globally unique preconfigured ATM address. Manual configuration is not required if you:

If you plan to migrate your flat network topology to a PNNI hierarchical topology, proceed to the next section "Configuring the Lowest Level of the PNNI Hierarchy."

Configuring the Lowest Level of the PNNI Hierarchy

This section describes how to configure the lowest level of the PNNI hierarchy. The lowest-level nodes comprise the lowest level of the PNNI hierarchy. When only the lowest-level nodes are configured, there is no hierarchical structure. If your network is relatively small and you want the benefits of PNNI, but do not need the benefits of a hierarchical structure, follow the procedures in this section to configure the lowest level of the PNNI hierarchy.

To implement multiple levels of PNNI hierarchy, first complete the procedures in this section and then proceed to the "Configuring Higher Levels of the PNNI Hierarchy" section.

Configuring an ATM Address and PNNI Node Level

The ATM switch router is preconfigured as a single lowest-level PNNI node (locally identified as node 1) with a level of 56. The node ID and peer group ID are calculated based on the current active ATM address.

Note   If you are planning to implement only a flat topology network (and have no future plans to migrate to PNNI hierarchy), you can skip this section and use the preconfigured ATM address.

To configure a node in a higher level of the PNNI hierarchy, the value of the node level must be a smaller number. For example, a three-level hierarchical network could progress from level 72 to level 64 to level 56. Notice that the level numbers graduate from largest at the lowest level (72) to smallest at the highest level (56).

To change the active ATM address you must create a new address, verify that it exists, and then delete the current active address. After you have entered the new ATM address, disable node 1 and then reenable it. At the same time, you can change the node level if required for your configuration. The identifiers for all higher level nodes are recalculated based on the new ATM address.

Caution   Node IDs and peer group IDs are not recalculated until the node is disabled and then reenabled.

To change the active ATM address, perform these steps, beginning in global configuration mode:

Example

The following example changes the ATM address of the switch from the autoconfigured address 47.0091.8100.0000.0041.0b0a.1081.0041.0b0a.1081.00 to the new address prefix 47.0091.8100.5670.0000.0000.1122.0041.0b0a.1081.00, and causes the node identifier and peer group identifier to be recalculated:

Displaying the PNNI Node Configuration

To display the ATM PNNI node configuration, use the following privileged EXEC command:

Example

The following example shows the PNNI node configuration using the show atm pnni local-node privileged EXEC command:

Configuring Static Routes

Because PNNI is a dynamic routing protocol, static routes are not necessary between nodes that support PNNI. However, you can extend the routing capability of PNNI beyond nodes that support PNNI to:

Use the atm route command to configure a static route. A static route attached to an interface allows all ATM addresses matching the configured address prefix to be reached through that interface.

Note   Two PNNI peer groups can be connected using the IISP protocol. Connecting PNNI peer groups requires that a static route be configured on the IISP interfaces, allowing connections to be set up across the IISP link(s).

To configure a static route connection, use the following global configuration command:

Examples

The following example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0/0:

The following example uses the atm route command to configure a static route to the 13-byte switch prefix 47.00918100000000410B0A1081 to ATM interface 0/0/0 configured with a scope 1 associated:

Displaying the Static Route Configuration

To display the ATM static route configuration, use the following EXEC command:

Example

The following example shows the ATM static route configuration using the show atm route EXEC command:

Configuring a Summary Address

You can configure summary addresses to reduce the amount of information advertised by a PNNI node and contribute to scalability in large networks. Each summary address consists of a single reachable address prefix that represents a collection of end system or node addresses. We recommend that you use summary addresses when all end system addresses that match the summary address are directly reachable from the node. However, this is not always required because routes are always selected by nodes advertising the longest matching prefix to a destination address.

By default, each lowest-level node has a summary address equal to the 13-byte address prefix of the ATM address of the switch. This address prefix is advertised into its peer group.

You can configure multiple addresses for a single switch which are used during ATM address migration. ILMI registers end systems with multiple prefixes during this period until an old address is removed. PNNI automatically creates 13-byte summary address prefixes from all of its ATM addresses.

You must configure summary addresses (other than the defaults) on each node. Each node can have multiple summary address prefixes. Use the s