Feature Overview

Whenever a partial or complete switched path exists between two hosts, packet forwarding occurs on Layer 3 switches. Packets without such a partial or complete switched path are still forwarded by routers to their destinations. Standard routing protocols such as Routing Information Protocol (RIP), Enhanced Interior Gateway Protocol (EIGRP), and NetWare Link Services Protocol (NLSP) are used for route determination.

IPX MLS also allows you to debug and trace flows in your network. Use MLS explorer packets to identify which switch is handling a particular flow. These packets aid you in path detection and troubleshooting. For complete information on debugging IPX MLS, see the section "Debug Commands" later in this document.

IPX MLS Components

An IPX MLS network topology has the following components:

Multilayer Switching-Switching Engine (MLS-SE)---Catalyst 5000 series switch with the Netflow Feature Card (NFFC II). The MLS-SE provides Layer 3 LAN-switching services.
Multilayer Switching-Route Processor (MLS-RP)---A Catalyst 5000 series Route Switch Module (RSM) or an externally connected Cisco 4500, 4700, 7200 or 7500 series router with software that supports MLS. The MLS-RP provides Cisco IOS-based multiprotocol routing, network services, and central configuration and control for the switches.
Multilayer Switching Protocol (MLSP)---The protocol running between the MLS-SE and MLS-RP that enables MLS.

IPX MLS Flows

Layer 3 protocols such as IP and IPX are connectionless---they deliver every packet independently of every other packet. However, actual network traffic consists of many end-to-end conversations, or flows, between users or applications.

A flow is a unidirectional packet sequence between a particular source and destination that share identical protocol and network-layer information. Communication flows from a client to a server and from the server to the client are distinct.

Flows are based only on Layer 3 addresses. If a destination IPX address identifies a flow, then IPX traffic from multiple users or applications to a particular destination can be carried on a single flow.

Layer 3 switched flows appear in the MLS cache, a special Layer 3 switching table maintained by the NFFC II. The cache contains traffic statistics entries that are updated in tandem with packet switching. After the MLS cache is created, packets identified as belonging to an existing flow can be Layer 3 switched. The MLS cache maintains flow information for all active flows.

M LS Cache

The MLS-SE maintains a cache for IPX MLS flows and maintains statistics for each flow. An IPX MLS cache entry is created for the initial packet of each flow. Upon receipt of a packet that does not match any flow in the MLS cache, a new IPX MLS entry is created.

The state and identity of the flow are maintained while packet traffic is active; when traffic for a flow ceases, the entry ages out. You can configure the aging time for IPX MLS entries kept in the MLS cache. If an entry is not used for the specified period of time, the entry ages out and statistics for that flow can be exported to a flow collector application.

The maximum MLS cache size is 128,000 entries. However, an MLS cache larger than 32,000 entries increases the probability that a flow will not be switched by the MLS-SE and will get forwarded to the router.

Note The number of active flows that can be switched using the MLS cache depends on the type of access lists configured on MLS router interfaces (which determines the flow mask). See the section "Flow Mask Modes" later in this document.

Flow Mask Modes

Two flow mask modes---destination mode and destination-source mode---determine how IPX MLS entries are created for the MLS-SE.

You determine the mode when you configure IPX access lists on the MLS-RP router interfaces. Each MLS-RP sends MLSP messages about its flow mask to the MLS-SE, which performs Layer 3 switching. The MLS-SE supports only the most specific flow mask for its MLS-RPs. If it detects more than one mask, it changes to the most specific one and purges the entire MLS cache. When an MLS-SE exports cached entries, it creates flow records from the most current flow mask mode. Depending on the current mode, some fields in the flow record might not have values. Unsupported fields are filled with a zero (0).

The two modes are described as follows:

Destination mode---The least-specific flow mask mode. The MLS-SE maintains one IPX MLS entry for each destination IPX address (network and node). All flows to a given destination IPX address use this IPX MLS entry. Use this mode if no access lists have been configured according to source IPX address on any of the IPX MLS router interfaces. In this mode the destination IPX address of the switched flows is displayed, along with the rewrite information: rewritten destination MAC, rewritten virtual LAN (VLAN), and egress port.
Destination-source mode---The MLS-SE maintains one MLS entry for each destination (network and node) and source (network only) IPX address pair. All flows between a given source and destination use this MLS entry regardless of the IPX sockets. Use this mode if an access list exists on any MLS-RP IPX interfaces that filter on source network.

Note The flow mask mode determines the display of the show mls rp ipx command. See the section "Command Reference" later in this document for details.

Layer 3 Switched Packet Rewrite

When a packet is Layer 3 switched from a source host to a destination host, the switch (MLS-SE) performs a packet rewrite based on information it learned from the router (MLS-RP) and then stored in the MLS cache.

If Host A and Host B are on different VLANs and Host A sends a packet to the MLS-RP to be routed to Host B, the MLS-SE recognizes that the packet was sent to the Media Access Control (MAC) address of the MLS-RP. The MLS-SE then checks the MLS cache and finds the entry matching the flow in question.

When the MLS-SE receives the packet, it is formatted as follows:

Frame Header Encap IPX Header Payload

Destination

Source

Length

Checksum/ IPX Length/ Transport Control¹

Packet Type

Destination Net/Node/ Socket

Source Net/Node/ Socket

Data

PAD/FCS

MLS-RP MAC

Host A MAC

Host B IPX

Host A IPX

¹Transport Control counts the number of times this packet has been routed. If this number is greater than the maximum (the default is 16), then the packet is dropped.

Frame Header	Encap	IPX Header	Payload
Destination	Source	Length	Checksum/ IPX Length/ Transport Control¹	Packet Type	Destination Net/Node/ Socket	Source Net/Node/ Socket	Data	PAD/FCS
MLS-RP MAC	Host A MAC			Host B IPX	Host A IPX

The MLS-SE rewrites the Layer 2 frame header, changing the destination MAC address to that of Host B and the source MAC address to that of the MLS-RP (these MAC addresses are stored in the IPX MLS cache entry for this flow). The Layer 3 IPX addresses remain the same. The MLS-SE rewrites the switched Layer 3 packets so that they appear to have been routed by a router.

The MLS-SE forwards the rewritten packet to Host B's VLAN (the destination VLAN is saved in the IPX MLS cache entry) and Host B receives the packet.

After the MLS-SE performs the packet rewrite, the packet is formatted as follows:

Frame Header Encap IPX Header Payload

Destination

Source

Length

Checksum/ IPX Length/ Transport Control

Packet Type

Destination Net/Node/ Socket

Source Net/Node/ Socket

Data

PAD/FCS

Host B MAC

MLS-RP MAC

Host B IPX

Host A IPX

Frame Header	Encap	IPX Header	Payload
Destination	Source	Length	Checksum/ IPX Length/ Transport Control	Packet Type	Destination Net/Node/ Socket	Source Net/Node/ Socket	Data	PAD/FCS
Host B MAC	MLS-RP MAC			Host B IPX	Host A IPX

IPX MLS Operation

Figure 1 shows a simple IPX MLS network topology:

Host A is on the Sales VLAN (IPX address 01.Aa).
Host B is on the Marketing VLAN (IPX address 03.Bb).
Host C is on the Engineering VLAN (IPX address 02.Cc).

When Host A initiates a file transfer to Host B, an IPX MLS entry for this flow is created (see the first item in Figure 1's table). When the MLS-RP forwards the first packet from A through the switch to B, the MLS-SE stores the MAC addresses of the MLS-RP and Host B in the IPX MLS entry. The MLS-SE uses this information to rewrite subsequent packets from A to B.

Similarly, a separate IPX MLS entry is created in the MLS cache for the traffic from Host A to Host C, and for the traffic from Host C to Host A. The destination VLAN is stored as part of each IPX MLS entry so that the correct VLAN identifier is used for encapsulating traffic on trunk links.

Figure 1: IPX MLS Example Topology

Standard Access Lists

Note Router interfaces with input access lists or outbound access lists unsupported by MLS cannot participate in IPX MLS. However, you can translate any input access list to an output access list to provide the same effect on the interface.

IPX MLS enforces access lists on every packet of the flow, without compromising IPX MLS performance. The MLS-SE handles permit traffic supported by MLS at wire speed.

Note Access list deny traffic is always handled by the MLS-RP, not the MLS-SE.

The MLS switching path automatically reflects route topology changes and the addition or modification of access lists on the MLS-SE. The techniques for handling route and access list changes apply to both the RSM and directly attached external routers.

For example, for Stations A and B to communicate, Station A sends the first packet to the MLS-RP. If the MLS-RP is configured with an access list to deny access from Station A to Station B, the MLS-RP receives the packet, checks its access list permissions to learn if the packet flow is permitted, and then discards the packet. Because the MLS-SE does not receive the returned first packet for this flow from the MLS-RP, the MLS-SE does not create an MLS cache entry.

In contrast, if the MLS-SE is already Layer 3 switching a flow and the access list is created on the MLS-RP, MLSP notifies the MLS-SE, and the MLS-SE immediately purges the affected flow from the MLS cache. New flows are created based on the restrictions imposed by the access list.

Similarly, when the MLS-RP detects a routing topology change, the MLS-SE deletes the appropriate MLS cache entries, and new flows are created based on the new topology.

Benefits

Reduces Load and Accelerates Delivery

With IPX MLS the router is responsible for routing only the first packet within a flow. Whenever a partial or complete switched path exists between two hosts, packet forwarding is shifted from the routers to a Layer 3 Catalyst 5000 series switch, thereby reducing router traffic and accelerating packet delivery to the destination.

Increases Switching Performance

MLS in the Catalyst 5000 series switch can switch IPX routed packets at speeds greater than one million packets per second.

Seamlessly Integrates with IPX Access Lists

Using a lightweight control protocol called the MLSP, Cisco IOS software running MLS can cause NFFC-II hardware to flush cache entries if either topology or access control lists change. The result is that the NFFC-II enforces access control lists based on both IP/IPX addresses and transport-layer information.

Re strictions

The following section describes restrictions that apply to configuring IPX MLS on the router.

General Configuration Guidelines

Be aware of the following:

You must configure the Catalyst 5000 series switch for IPX MLS to work.
When you enable IPX MLS, the RSM or externally attached router continues to handle all non-IPX protocols, while off-loading the switching of IPX packets to the MLS-SE.
Do not confuse IPX MLS with NetFlow switching supported by Cisco routers. IPX MLS requires both the RSM or directly attached external router and the MLS-SE, but not NetFlow switching on the RSM or directly attached external router. Any switching path on the RSM or directly attached external router will function (process, fast, optimum, and so on).

External Router Guidelines

Follow these guidelines when using an external router:

Use one directly attached external router per switch to ensure that the MLS-SE caches the appropriate flow information from both sides of the routed flow.
Use Cisco high-end routers (Cisco 4500, 4700, 7200, and 7500 series) for IPX MLS when they are externally attached to the switch. Make the attachment with multiple Ethernet connections (one per subnet) or by using Fast or Gigabit Ethernet with Inter-Switch Link (ISL) or IEEE 802.1Q encapsulation.
Connect end hosts through any media (Ethernet, Fast Ethernet, ATM, and Fiber Distributed Data Interface [FDDI]), but connect the external router and the switch only through standard 10/100 Ethernet interfaces, ISL, or IEEE 802.1Q links.

Access L ist Restrictions

The following restrictions apply when you use access lists on interfaces that participate in IPX MLS:

Input access lists---Router interfaces with input access lists cannot participate in IPX MLS. If you configure an input access list on an interface, no packets inbound or outbound for that interface are Layer 3 switched, even if the flow is not filtered by the access list. Existing flows for that interface are purged, and no new flows are cached.

Note

Output access lists---When an output access list is applied to an interface, the IPX MLS cache entries for that interface are purged. Entries associated with other interfaces are not affected; they follow their normal aging or purging procedures.

: Applying access lists that filter according to packet type, source node, source socket, or destination socket prevents the interface from participating in IPX MLS.
: Applying access lists that use the log option prevents the interface from participating in IPX MLS.

Access list impact on flow masks---Access lists impact the flow mask mode advertised to the MLS-SE by an MLS-RP. If no access list has been applied on any MLS-RP interface, the flow mask mode is destination-ipx (the least specific) by default. If an access list that filters according to the source IPX network has been applied, the mode is source-destination-ipx by default.

Restrictions on Interaction of IPX MLS with Other Features

IPX MLS affects other Cisco IOS software features as follows:

IPX accounting---IPX accounting cannot be enabled on an IPX MLS-enabled interface.
IPX EIGRP---MLS is supported for EIGRP interfaces if the Transport Control (TC) maximum is set to a value greater than the default (16).

Restricti on on Maximum Transmission Unit Size

In IPX the two endpoints of communication negotiate the maximum transmission unit (MTU) to be used. MTU size is limited by media type.

Related Features and Technologies

Switching
IPX routing

Sup ported Platforms

Cisco 3600 series
Cisco 4500 series
Cisco 7200 series
Cisco 7500 series
Catalyst 5000 series Route Switch Module (RSM)
Catalyst 8500 Campus Switch Router (CSR)

Supported Standards, MIBs, and RFCs

MIBs

CISCO-SWITCH-ENGINE-MIB
CISCO-MLS-RP-MIB

For descriptions of supported MIBs and how to use MIBs, see the Cisco MIB web site on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.

RFCs

None

Standards

None

Prerequi sites

The following prerequisites must be met before IPX MLS can function:

A VLAN interface must be configured on both the switch and the router. For information on configuring inter-VLAN routing on the RSM or external router, refer to the Catalyst 5000 Software Configuration Guide, Release 5.1.
IPX MLS must be configured on the switch. For more information refer to the Catalyst 5000 Software Configuration Guide, Release 5.1 and the Catalyst 5000 Command Reference, Release 5.1.
IPX MLS must be enabled on the router. The minimal configuration steps are described in the section "Configuration Tasks." For more details on configuring IPX routing, refer to the Cisco IOS Release 12.0 Network Protocols Configuration Guide, Part 2.

Configuration Tasks

Perform the following tasks to configure one or more routers for IPX MLS. The number of tasks you perform depends on your particular configuration.

Adding an IPX MLS Interface to a Virtual Trunk Protocol (VTP) Domain (Optional)
Enabling Multilayer Switching Protocol (MLSP) on the Router (Required)
Assigning a VLAN ID to a Router Interface (Optional)
Enabling IPX MLS on a Router Interface (Required)
Specifying a Router Interface as a Management Interface (Required)

For examples of IPX MLS configurations, see the "Configuration Examples" section later in this document.

Adding an IPX M LS Interface to a Virtual Trunk Protocol (VTP) Domain

Caution
Perform this configuration task only if the switch connected to your router interfaces is in a VTP domain. Perform the task before you enter any other IPX MLS interface command---specifically the mls rp ipx or mls rp management-interface commands. If you enter these commands before adding the interface to a VTP domain, the interface will be automatically placed in a null domain. To place the IPX MLS interface into a domain other than the null domain, clear the IPX MLS interface configuration before you add the interface to another VTP domain. See the section "Configuration, Verification, and Troubleshooting Tips" and the Catalyst 5000 Software Configuration Guide, Release 5.1.

Determine which router interfaces you will use as IPX MLS interfaces and add them to the same VTP domain as the switches.

To view the VTP configuration and its domain name on the switch, enter the
show mls rp vtp-domain command at the switch Console> prompt.

To assign an MLS interface to a specific VTP domain on the MLS-RP, use the mls rp vtp-domain interface configuration command.

Command Purpose

Router(config-if)# mls rp vtp-domain domain-name
Adds an IPX MLS interface to a Virtual Trunk Protocol (VTP) domain.

Command	Purpose
Router(config-if)# mls rp vtp-domain domain-name	Adds an IPX MLS interface to a Virtual Trunk Protocol (VTP) domain.

Enabling Multilayer Switchin g Protocol (MLSP) on the Router

To enable MLSP on the router, use the mls rp ipx global configuration command.

Command Purpose

Router(config)# mls rp ipx
Globally enables MLSP on the router. MLSP is the protocol that runs between the MLS-SE and MLS-RP.

Command	Purpose
Router(config)# mls rp ipx	Globally enables MLSP on the router. MLSP is the protocol that runs between the MLS-SE and MLS-RP.

Assigning a VLAN I D to a Router Interface

Note This task is not required for RSM VLAN interfaces (virtual interfaces), ISL-encapsulated interfaces, or IEEE 802.1Q-encapsulated interfaces.

To assign a VLAN ID to an IPX MLS interface, use the mls rp vlan-id interface configuration command.

Command Purpose

Router(config-if)# mls rp vlan-id vlan-id-number
Assigns a VLAN ID to an IPX MLS interface. The assigned IPX MLS interface must be either an Ethernet or Fast Ethernet interface with no subinterfaces.

Command	Purpose
Router(config-if)# mls rp vlan-id vlan-id-number	Assigns a VLAN ID to an IPX MLS interface. The assigned IPX MLS interface must be either an Ethernet or Fast Ethernet interface with no subinterfaces.

Enabling IPX M LS on a Router Interface

Command Purpose

Router(config-if)# mls rp ipx
Enables a router interface for IPX MLS.

To enable IPX MLS on a router interface, use the mls rp ipx interface configuration command.

Command	Purpose
Router(config-if)# mls rp ipx	Enables a router interface for IPX MLS.

Specifying a Rou ter Interface as a Management Interface

To specify an interface as the management interface, use the mls rp management-interface interface configuration command.

Command Purpose

Router(config-if)# mls rp management-interface
Specifies an interface as the management interface. MLSP packets are sent and received through the management interface. Select only one IPX MLS interface connected to the switch.

Command	Purpose
Router(config-if)# mls rp management-interface	Specifies an interface as the management interface. MLSP packets are sent and received through the management interface. Select only one IPX MLS interface connected to the switch.

Verifying IPX MLS on the Router

To verify that you have correctly installed IPX MLS on the router, perform the following steps:

Step 1 Enter the show mls rp ipx command.

Step 2 Examine the output to learn if the VLANs are enabled.

Step 3 Examine the output to learn if the switches are listed by MAC address, indicating they are recognized by the MLS-RP.

Troubleshooting Tips

If you entered either the mls rp ipx command or the mls rp management-interface command on the interface before assigning it to a Virtual Trunk Protocol (VTP) domain, the interface will be in the null domain, instead of the VTP domain.

To remove the interface from the null domain and add it to a new VTP domain, use the following commands in interface configuration mode:

Step Command Purpose

1 .

Router(config-if)# no mls rp ipx
Router(config-if)# no mls rp management-interface
Router(config-if)# no mls rp vtp-domain domain-name

Removes an interface from the null domain.

2 .

Router(config-if)# mls rp vtp-domain domain-name
Adds the interface to a new Virtual Trunk Protocol (VTP) domain.

Monito ring and Maintaining IPX MLS on the Router

Command Purpose

Router# mls rp locate ipx

Displays information about all switches currently shortcutting for the specified IPX flow(s).

Router# show mls rp interface type number

Displays MLS details for a specific interface.

Router# show mls rp ipx

Displays details for all IPX MLS interfaces on the router: MLS status (enabled or disabled) for switch interfaces and subinterfaces; flow mask required when creating Layer 3 switching entries for the router; current settings for the keepalive timer, retry timer, and retry count; MLSP-ID used in MLSP messages; and list of interfaces in all Virtual Trunk Protocol (VTP) domains enabled for MLS.

Router# show mls rp vtp-domain domain-name

Displays details about IPX MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain.

Command	Purpose
Router# mls rp locate ipx	Displays information about all switches currently shortcutting for the specified IPX flow(s).
Router# show mls rp interface type number	Displays MLS details for a specific interface.
Router# show mls rp ipx	Displays details for all IPX MLS interfaces on the router: MLS status (enabled or disabled) for switch interfaces and subinterfaces; flow mask required when creating Layer 3 switching entries for the router; current settings for the keepalive timer, retry timer, and retry count; MLSP-ID used in MLSP messages; and list of interfaces in all Virtual Trunk Protocol (VTP) domains enabled for MLS.
Router# show mls rp vtp-domain domain-name	Displays details about IPX MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain.

Configuration Examples

This section provides a complex IPX MLS network example: the Cisco 7505 switch over ISL. The example includes router and switch configurations, even though switch commands are not documented in this router publication. The section also includes sample configurations with no access lists and with standard access lists. Refer to the Catalyst 5000 Command Reference, Release 5.1 for more information.

Complex IPX MLS Network Example

Figure 2 shows an IPX MLS network topology consisting of three Catalyst 5000 series switches and a Cisco 7505 router---all interconnected with ISL trunk links. The network is configured as follows:

There are four VLANs (IPX networks):
- VLAN 1 (management VLAN), IPX network 1
- VLAN 10, IPX network 10
- VLAN 20, IPX network 20
- VLAN 30, IPX network 30
The Multilayer Switching-Route Processor is a Cisco 7505 router with a Fast Ethernet interface (interface fastethernet2/0)
The subinterfaces on the router interface have the following IPX network addresses:
- fastethernet2/0.1-IPX network 1
- fastethernet2/0.10-IPX network 10
- fastethernet2/0.20-IPX network 20
- fastethernet2/0.30-IPX network 30
Switch A, the MLS-SE Virtual Trunk Protocol (VTP) server, is a Catalyst 5509 switch with Supervisor Engine III and the NFFC II
Switch B and Switch C are Virtual Trunk Protocol (VTP) client Catalyst 5505 switches

Figure 2: Example Networ k: IPX MLS with Cisco 7505 over ISL

Op eration Before IPX MLS

Before IPX MLS is implemented, when the source host NC1 (on VLAN 10) sends traffic destined for destination server NS2 (on VLAN 30), Switch B forwards the traffic (based on the Layer 2 forwarding table) to Switch A over the ISL trunk link. Switch A forwards the packet to the router over the ISL trunk link.

The router receives the packet on the VLAN 10 subinterface, checks the destination IPX address, and routes the packet to the VLAN 30 subinterface. Switch A receives the routed packet and forwards it to Switch C. Switch C receives the packet and forwards it to destination server NS2. This process is repeated for each packet in the flow between source host NC1 and destination server NS2.

Operation Af ter IPX MLS

After IPX MLS is implemented, when the source host NC1 (on VLAN 10) sends traffic destined for destination server NS2 (on VLAN 30), Switch B forwards the traffic (based on the Layer 2 forwarding table) to Switch A (the MLS-SE) over the ISL trunk link. When the first packet enters Switch A, a candidate flow entry is established in the MLS cache. Switch A forwards the packet to the MLS-RP over the ISL trunk link.

The MLS-RP receives the packet on the VLAN 10 subinterface, checks the destination IPX address, and routes the packet to the VLAN 30 subinterface. Switch A receives the routed packet (the enabler packet) and completes the flow entry in the MLS cache for the destination IPX address of NS2. Switch A forwards the packet to Switch C, where it is forwarded to destination server NS2.

Subsequent packets destined for the IPX address of NS2 are multilayer switched by the MLS-SE based on the flow entry in the MLS cache. For example, subsequent packets in the flow from source host NC1 are forwarded by Switch B to Switch A (the MLS-SE). The MLS-SE determines that the packets are part of the established flow, rewrites the packet headers, and switches the packets directly to Switch C, bypassing the router.

Switch A Configuration

This example shows how to configure Switch A (MLS-SE):

SwitchA> (enable) set vtp domain Corporate mode server
VTP domain Corporate modified
SwitchA> (enable) set vlan 10
Vlan 10 configuration successful
SwitchA> (enable) set vlan 20
Vlan 20 configuration successful
SwitchA> (enable) set vlan 30
Vlan 30 configuration successful
SwitchA> (enable) set port name 1/1 Router Link
Port 1/1 name set.
SwitchA> (enable) set trunk 1/1 on isl
Port(s) 1/1 trunk mode set to on.
Port(s) 1/1 trunk type set to isl.
SwitchA> (enable) set port name 1/2 SwitchB Link
Port 1/2 name set.
SwitchA> (enable) set trunk 1/2 desirable isl
Port(s) 1/2 trunk mode set to desirable.
Port(s) 1/2 trunk type set to isl.
SwitchA> (enable) set port name 1/3 SwitchC Link
Port 1/3 name set.
SwitchA> (enable) set trunk 1/3 desirable isl
Port(s) 1/3 trunk mode set to desirable.
Port(s) 1/3 trunk type set to isl.
SwitchA> (enable) set mls enable ipx
IPX Multilayer switching is enabled.
SwitchA> (enable) set mls include ipx 10.1.1.1
IPX Multilayer switching enabled for router 10.1.1.1.
SwitchA> (enable) set port name 3/1 Destination D2
Port 3/1 name set.
SwitchA> (enable) set vlan 20 3/1
VLAN 20 modified.
VLAN 1 modified.
VLAN  Mod/Ports
---- -----------------------
20    3/1
      
SwitchA> (enable)

Switch B Co nfiguration

This example shows how to configure Switch B:

SwitchB> (enable) set port name 1/1 SwitchA Link
Port 1/1 name set.
SwitchB> (enable) set port name 3/1 Source S1
Port 3/1 name set.
SwitchB> (enable) set vlan 10 3/1
VLAN 10 modified.
VLAN 1 modified.
VLAN  Mod/Ports
---- -----------------------
10    3/1
      
SwitchB> (enable)

Switch C Configuration

This example shows how to configure Switch C:

SwitchC> (enable) set port name 1/1 SwitchA Link
Port 1/1 name set.
SwitchC> (enable) set port name 3/1 Destination D1
Port 3/1 name set.
SwitchC> (enable) set vlan 30 3/1
VLAN 30 modified.
VLAN 1 modified.
VLAN  Mod/Ports
---- -----------------------
30    3/1
      
SwitchC> (enable) set port name 4/1 Source S2
Port 4/1 name set.
SwitchC> (enable) set vlan 30 4/1
VLAN 30 modified.
VLAN 1 modified.
VLAN  Mod/Ports
---- -----------------------
30    3/1
      4/1
      
SwitchC> (enable)

Configuring a Router

This example configures the Multilayer Switching-Route Processor:

mls rp ipx
interface fastethernet 2/0
full-duplex
mls rp vtp-domain Engineering
interface fastethernet2/0.1
encapsulation isl 1
ipx address 10.1.1.1 255.255.255.0
mls rp ipx
mls rp management-interface
interface fastethernet2/0.10
encapsulation isl 10
ipx network 10
mls rp ipx
interface fastethernet2/0.20
encapsulation isl 20
ipx network  20
mls rp ipx
interface fastethernet2/0.30
encapsulation isl 30
ipx network 30
mls rp ipx

Configuring a Router with No Access Lists

This example configures the RSM VLAN interfaces with no access lists. Therefore the flow mask mode is destination.

Building configuration...
 
Current configuration:
!
version 12.0
 
.
.
 
ipx routing 0010.0738.2917
mls rp ip 
mls rp ipx
 
.
.
 
interface Vlan21
 ip address 5.5.5.155 255.255.255.0
 ipx network 2121
 mls rp vtp-domain Engineering
 mls rp management-interface
 mls rp ip
 mls rp ipx
!
interface Vlan22
ip address 2.2.2.155 255.255.255.0
 ipx network 2222
 mls rp vtp-domain Engineering
 mls rp ip
 mls rp ipx
!
.
.
end

Configuri ng a Router with a Standard Access List

This example configures a standard access list on the RSM VLAN 3 interface. Therefore, the flow mask mode is destination-source.

Router#show run
Building configuration...
Current configuration:
!
version 12.0
!
interface Vlan22
ip address 2.2.2.155 255.255.255.0
 ipx access-group 800 out
 ipx network 2222
 mls rp vtp-domain Engineering
 mls rp ip
 mls rp ipx
!
 
.
.
 
!
!
!
 
access-list 800 deny 1111 2222
access-list 800 permit FFFFFFFF FFFFFFFF
 
.
.
 
end

Command Reference

This section documents new or modified commands that configure IPX Multilayer Switching on a router. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command reference publications, the Catalyst 5000 Software Configuration Guide, Release 5.1, and the Catalyst 5000 Command Reference, Release 5.1.

In Cisco IOS Release 12.0(1)T or later, you can search and filter the output for show and more commands. This functionality is useful when you need to sort through large amounts of output, or if you want to exclude output that you do not need to see.

To use this functionality, enter a show or more command followed by the "pipe" character (|), one of the keywords begin, include, or exclude, and an expression that you want to search or filter on:

command | {begin | include | exclude} regular-expression

Following is an example of the show atm vc command in which you want the command output to begin with the first line where the expression "PeakRate" appears:

show atm vc | begin PeakRate

For more information on the search and filter functionality, refer to the Cisco IOS Release 12.0(1)T feature module titled CLI String Search.

mls rp ip x (global)

Note This command can be used in either global configuration or interface configuration mode.

To enable the router as an IPX Multilayer Switching Route Processor, use the mls rp ipx global configuration command. To disable IPX MLS on the router, use the no form of this command.

mls rp ipx
no mls rp ipx

Syntax Description

This command has no arguments or keywords.

Defaults

There are no default behavior or values.

Command Modes

Global configuration

Command History


Release	Modification
12.0(5)T	This command was introduced.

Usage Guidelines

Multilayer Switching Protocol (MLSP) is the protocol that runs between the MLS-Switching Engine and the MLS-Route Processor.

Examples

The following example enables IPX MLS on the Multilayer Switching-Route Processor:

Router (config)# mls rp ipx

Related Commands


Command	Description
mls rp locate ipx	In privileged EXEC mode displays information about all switches currently shortcutting for the specified IPX flow(s).
mls rp management-interface	In interface configuration mode specifies an interface as the management interface.
mls rp vlan-id	In interface configuration mode assigns a VLAN ID to an IPX MLS interface.
mls rp vtp-domain	In interface configuration mode assigns an MLS interface to a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.
show mls rp interface	In privileged EXEC mode displays IPX MLS information specific to an interface.
show mls rp ipx	In privileged EXEC mode displays details for all IPX MLS interfaces on the IPX Multilayer Switching-Route Processor.
show mls rp vtp-domain	In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

mls rp ipx (interface)

Note This command can be used in either global configuration or interface configuration mode.

To enable IPX MLS on a router interface, use the mls rp ipx interface configuration command. To disable IPX MLS on a router interface, use the no form of this command.

mls rp ipx
no mls rp ipx

Syntax Description

This command has no arguments or keywords.

Defaults

There are no default behavior or values.

Command Modes

Interface configuration

Command History


Release	Modification
12.0(5)T	This command was introduced.

Usage Guidelines

Multilayer Switching Protocol (MLSP) is the protocol that runs between the MLS-Switching Engine and the MLS-Route Processor.

Examples

The following example enables IPX MLS on a router interface:

Router (config-if)# mls rp ipx

Related Commands


Command	Description
mls rp locate ipx	In privileged EXEC mode displays information about all switches currently shortcutting for the specified IPX flow(s).
mls rp management-interface	In interface configuration mode specifies an interface as the management interface.
mls rp vlan-id	In interface configuration mode assigns a VLAN ID to an IPX MLS interface.
mls rp vtp-domain	In interface configuration mode assigns an MLS interface to a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.
show mls rp interface	In privileged EXEC mode displays IPX MLS information specific to an interface.
show mls rp ipx	In privileged EXEC mode displays details for all IPX MLS interfaces on the IPX Multilayer Switching-Route Processor.
show mls rp vtp-domain	In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

mls rp loca te ipx

To display information about all switches currently shortcutting for the specified IPX flow(s), use the mls rp locate ipx privileged EXEC command.

mls rp locate ipx destination-network.destination-node [source-network]

Syntax Description


destination-network.destination-node	The destination network and destination node of IPX packet flows. The destination network consists of 1 to 8 hexadecimal numbers in the format xxxxxxxx. The destination node consists of 1 to 12 hexadecimal numbers in the format xxxx.xxxx.xxxx.
source-network	(Optional) The source network of the IPX flow. The source network consists of 1 to 8 hexadecimal numbers in the format yyyyyyyy.

Defaults

None

Command Modes

Privileged EXEC

Command History


Release	Modification
12.0(5)T	This command was introduced.

Examples

This example displays the switch that is shortcutting routed flows to the specified IPX flow:

Router# mls rp locate ipx 30.0000.1111.2222
locator response from switch id 0010.1400.601f

Related Commands


Command	Description
mls rp ipx	In global configuration mode enables MLSP on the router. In interface configuration mode enables IPX MLS on a router interface.
mls rp management-interface	In interface configuration mode specifies an interface as the management interface.
mls rp vlan-id	In interface configuration mode assigns a VLAN ID to an IPX MLS interface.
mls rp vtp-domain	In interface configuration mode assigns an MLS interface to a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.
show mls rp interface	In privileged EXEC mode displays IPX MLS information specific to an interface.
show mls rp ipx	In privileged EXEC mode displays details for all IPX MLS interfaces on the IPX Multilayer Switching-Route Processor.
show mls rp vtp-domain	In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

mls rp management-interface

To specify an interface as the management interface, use the mls rp management-interface interface configuration command. To remove an interface as the management interface, use the no form of the command

mls rp management-interface
no mls rp management-interface

Syntax Description

This command has no keywords or arguments.

Defaults

None

Command Modes

Interface configuration

Command History


Release	Modification
12.0(5)T	This command was introduced.

Usage Guidelines

Multilayer Switching Protocol (MLSP) packets are sent and received through the management interface.

Select only one IPX Multilayer Switching interface connected to the switch. If you fail to select this interface, no connection between the Multilayer Switch (MLS) Route Processor and the Multilayer Switch Switching Engine will occur, and any routing updates or changes to access lists will not be reflected on the switch.

Examples

The following example selects a management interface:

mls rp management-interface

Related Commands


Command	Description
mls rp ipx	In global configuration mode enables MLSP on the router. In interface configuration mode enables IPX MLS on a router interface.
mls rp locate ipx	In privileged EXEC mode displays information about all switches currently shortcutting for the specified IPX flow(s).
mls rp vlan-id	In interface configuration mode assigns a VLAN ID to an IPX MLS interface.
mls rp vtp-domain	In interface configuration mode assigns an MLS interface to a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.
show mls rp interface	In privileged EXEC mode displays IPX MLS information specific to an interface.
show mls rp ipx	In privileged EXEC mode displays details for all IPX MLS interfaces on the IPX Multilayer Switching-Route Processor.
show mls rp vtp-domain	In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

mls rp vlan-id

To assign a virtual LAN (VLAN) identification number to an IPX MLS interface, use the mls rp vlan-id interface configuration command. To remove a VLAN identification number, use the no form of the command.

mls rp vlan-id vlan-id-number
no mls rp vlan-id vlan-id-number

Syntax Description


vlan-id-number	A VLAN identification number between 1 and 4096.

Defaults

None

Command Modes

Interface configuration

Command History


Release	Modification
12.0(5)T	This command was introduced.

Usage Guidelines

The assigned IPX MLS interface must be either an Ethernet or Fast Ethernet interface---both without subinterfaces.

Examples

This example assigns a the VLAN identification number 23 to an IPX MLS interface:

mls rp vlan-id 23

Related Commands


Command	Description
mls rp ipx	In global configuration mode enables MLSP on the router. In interface configuration mode enables IPX MLS on a router interface.
mls rp locate ipx	In privileged EXEC mode displays information about all switches currently shortcutting for the specified IPX flow(s).
mls rp management-interface	In interface configuration mode specifies an interface as the management interface.
mls rp vtp-domain	In interface configuration mode assigns an MLS interface to a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.
show mls rp interface	In privileged EXEC mode displays IPX MLS information specific to an interface.
show mls rp ipx	In privileged EXEC mode displays details for all IPX MLS interfaces on the IPX Multilayer Switching-Route Processor.
show mls rp vtp-domain	In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

mls rp vtp-domain

To assign a Multilayer Switching (MLS) interface to a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor, use the mls rp vtp-domain interface configuration command. To remove a VTP domain, use the no form of the command.

mls rp vtp-domain domain-name
no mls rp vtp-domain domain-name

Syntax Description

domain-name

The name of the Virtual Trunk Protocol (VTP) domain assigned to an MLS interface and its related switches.

domain-name	The name of the Virtual Trunk Protocol (VTP) domain assigned to an MLS interface and its related switches.

Defaults

The interface is assigned to the null domain.

Command Modes

Interface configuration

Command History


Release	Modification
12.0(5)T	This command was introduced.

Usage Guidelines

The assigned IPX MLS interface must be either an Ethernet or Fast Ethernet interface---both without subinterfaces.

Examples

This example assigns the MLS interface to the VTP domain called "engineering:"

mls rp vtp-domain engineering

Related Commands


Command	Description
mls rp ipx	In global configuration mode enables MLSP on the router. In interface configuration mode enables IPX MLS on a router interface.
mls rp locate ipx	In privileged EXEC mode displays information about all switches currently shortcutting for the specified IPX flow(s).
mls rp management-interface	In interface configuration mode specifies an interface as the management interface.
mls rp vlan-id	In interface configuration mode assigns a VLAN ID to an IPX MLS interface.
show mls rp interface	In privileged EXEC mode displays IPX MLS information specific to an interface.
show mls rp ipx	In privileged EXEC mode displays details for all IPX MLS interfaces on the IPX Multilayer Switching-Route Processor.
show mls rp vtp-domain	In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

show m ls rp interface

To display IPX Multilayer Switching (MLS) details for the route processor, including specific information about the Multilayer Switching Protocol (MLSP), use the show mls rp interface privileged EXEC command.

show mls rp interface type number

Syntax Description

type

Interface type.

number

Interface number.

Defaults

None

Command Modes

Privileged EXEC

Command History


Release	Modification
12.0(5)T	This command was introduced.

Examples

The following displays sample output from the show mls rp interface command. The interface type is VLAN, and its number is 10.

Router# show mls rp interface vlan 10
IPX MLS active on Vlan 10, domain WBU

Related Commands


Command	Description
mls rp ipx	In global configuration mode enables MLSP on the router. In interface configuration mode enables IPX MLS on a router interface.
mls rp locate ipx	In privileged EXEC mode displays information about all switches currently shortcutting for the specified IPX flow(s).
mls rp vtp-domain	In interface configuration mode assigns an MLS interface to a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.
mls rp management-interface	In interface configuration mode specifies an interface as the management interface.
mls rp vlan-id	In interface configuration mode assigns a VLAN ID to an IPX MLS interface.
show mls rp ipx	In privileged EXEC mode displays details for all IPX MLS interfaces on the IPX Multilayer Switching-Route Processor.
show mls rp vtp-domain	In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

sho w mls rp ipx

To display details for all IPX Multilayer Switching (MLS) interfaces on the IPX MLS router, use the show mls rp ipx privileged EXEC command.

show mls rp ipx

Syntax Description

This command has no keywords or arguments.

Command Modes

Privileged EXEC

Command History


Release	Modification
12.0(5)T	This command was introduced.

Usage Guidelines

This command gives you details about the following:

MLS status (enabled or disabled) for switch interfaces and subinterfaces
Flow mask required when creating Layer 3 switching entries for the router
current settings for the keepalive timer, retry timer, and retry count
MLS identifier used in Multilayer Switching Protocol (MLSP) messages
List of all interfaces in all Virtual Trunk Protocol (VTP) domains enabled for MLS

Examples

The following example displays sample output from the show mls rp ipx command for all IPX MLS interfaces on an MLS-RP:

Router# show mls rp ipx
ipx multilayer switching is globally enabled
ipx mls inbound acl override is globally disabled
mls id is 0050.73ff.b580
mls ip address 5.5.5.155
IPX MLS flow mask is source-destination
number of domains configured for mls 1
 
vlan domain name:Engineering
   current ipx flow mask:source-destination
   ipx current/next global purge:false/false
   ipx current/next purge count:0/0
   current sequence number:4086390283
   current/maximum retry count:0/10
   current domain state:no-change
   domain uptime:03:13:09
   keepalive timer expires in 3 seconds
   retry timer not running
   change timer not running

   1 management interface(s) currently defined:
      vlan 21 on Vlan21

   2 mac-vlan(s) enabled for ipx multi-layer switching:

      mac 0010.0738.2917
         vlan id(s)
         22   
 
      mac 0050.73ff.b5b8
         vlan id(s)
         21

   router currently aware of following 1 switch(es):
      switch id 00e0.fe4a.aeff

Related Commands

Command Description

mls rp ipx

In global configuration mode enables MLSP on the router. In interface configuration mode enables IPX MLS on a router interface.

mls rp locate ipx

In privileged EXEC mode displays information about all switches currently shortcutting for the specified IPX flow(s).

mls rp management-interface

In interface configuration mode specifies an interface as the management interface.

mls rp vlan-id

In interface configuration mode assigns a VLAN ID to an IPX MLS interface.

show mls rp vtp-domain

In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

show mls rp interface

In privileged EXEC mode displays IPX MLS information specific to an interface.

show mls rp vtp-domain

In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.

show ml s rp vtp-domain

To display IPX Multilayer Switching (MLS) interfaces for a specific Virtual Trunk Protocol (VTP) domain on the route processor, use the show mls rp vtp-domain privileged EXEC command.

show mls rp vtp-domain domain-name

Syntax Description

domain-name

The name of the Virtual Trunk Protocol (VTP) domain whose MLS interfaces will be displayed.

Defaults

None

Command Modes

Privileged EXEC

Command History


Release	Modification
12.0(5)T	This command was introduced.

Examples

This examples shows details about IPX MLS interfaces in a VTP domain called WBU:

Router# show mls rp vtp-domain WBU
vlan domain name: WBU
current ipx flow mask: destination
   ipx current/next global purge: false/false
   ipx current/next purge count: 0/0
   current ipx flow mask: destination
   ipx current/next global purge: false/false
   ipx current/next purge count: 0/0
   current sequence number: 590678296
   current/maximum retry count: 0/10
   current domain state: no-change
   domain uptime: 1d14h
   keepalive timer expires in 3 seconds
   retry timer not running
   change timer not running
   fcp subblock count = 20

   1 management interface(s) currently defined:
      vlan 2 on Vlan2

   20 mac-vlan(s) configured for multi-layer switching

   17 mac-vlan(s) enabled for ipx multi-layer switching:

      mac 0010.0738.2917
         vlan id(s)

         2    3    4    5    6    7    8    9    10   12   13
         14   15   88   99

      mac 0090.6dfc.5800
         vlan id(s)
         20   21

   18 mac-vlan(s) enabled for ipx multi-layer switching:

      mac 0010.0738.2917
         vlan id(s)
         2    3    4    5    6    7    8    9    10   11   12
         13   14   15   66   77   88   99

   router currently aware of following 1 switch(es):
      switch id 0010.141f.6fff

Related Commands


Command	Description
mls rp ipx	In global configuration mode enables MLSP on the router. In interface configuration mode enables IPX MLS on a router interface.
mls rp locate ipx	In privileged EXEC mode displays information about all switches currently shortcutting for the specified IPX flow(s).
mls rp management-interface	In interface configuration mode specifies an interface as the management interface.
mls rp vlan-id	In interface configuration mode assigns a VLAN ID to an IPX MLS interface.
show mls rp vtp-domain	In privileged EXEC mode displays MLS interfaces for a specific Virtual Trunk Protocol (VTP) domain on the Multilayer Switching-Route Processor.
show mls rp interface	In privileged EXEC mode displays IPX MLS information specific to an interface.
show mls rp ipx	In privileged EXEC mode displays details for all IPX MLS interfaces on the IPX Multilayer Switching-Route Processor.

Debug Commands

This section documents the new debug commands related to the IPX Multilayer Switching feature.

debug dss ipx event
debug mls rp


Release	Modification
12.0(5)T	This command was introduced.

Examples

The following displays sample output from the debug dss ipx event command:

Router# debug dss ipx event
DSS IPX events debugging is on

Router# conf t
Enter configuration commands, one per line.  End with CNTL/Z.

Router(config)# int vlan 22
Router(config-if)# ipx access-group 800 out
05:51:36:DSS-feature:dss_ipxcache_version():idb:NULL, reason:42,
prefix:0, mask:FFFFFFFF
05:51:36:DSS-feature:dss_ipx_access_group():idb:Vlan22
05:51:36:DSS-feature:dss_ipx_access_list()
05:51:36:DSS-base 05:51:33.834 dss_ipx_invalidate_interface Vl22
05:51:36:DSS-base 05:51:33.834 dss_set_ipx_flowmask_reg 2
05:51:36:%IPX mls flowmask transition from 1 to 2 due to new status of
simple IPX access list on interfaces

Related Commands


Command	Description
debug mls rp	Displays various MLS debugging elements.

debug mls rp

To display various IPX Multilayer Switching (MLS) debugging elements, use the debug mls rp command. To disable debugging output, use the no form of the command.

[no] debug mls rp {error | events | ipx | locator | packets | all}

Syntax Description


error	Displays MLS error messages.
events	Displays a run-time sequence of events for the Multilayer Switching Protocol (MLSP).
ipx	Displays IPX-related events for MLS, including route purging and changes to access lists and flow masks.
locator	Identifies which switch is switching a particular flow of MLS explorer packets.
packets	Displays packet contents (in verbose and hexadecimal formats) for MLSP messages.
all	Displays all MLS debugging events.

Defaults

Debugging is not enabled.

Command History


Release	Modification
12.0(5)T	This command was introduced.

Examples

The following example shows output using the debug mls rp ipx command.

Router# debug mls rp ipx
IPX MLS debugging is on

Router# conf t
Enter configuration commands, one per line.  End with CNTL/Z.

Router(config)# int vlan 22
Router(config-if)# no ipx access-group out
05:44:37:FCP:flowmask changed to destination

Related Commands


Command	Description
debug dss ipx event	Displays debug messages for route change events that affect IPX MLS.

Glossary

MLSP---The protocol running between the MLS-SE and MLS-RP to enable Multilayer Switching.

MLS-RP---A Cisco router with MLS enabled.

MLS-SE---A Catalyst 5000 series switch equipped with a NetFlow Feature Card.

Multilayer Switching Protocol---See MLSP.

Multilayer Switching-Route Processor---See MLS-RP.

Multilayer Switching-Switching Engine---See MLS-SE.

Netflow Feature Card---See NFCC.

NFFC---A card on the switch that enables MLS Layer3 switching to occur.

Table of Contents

IPX Multilayer Switching

Feature Overview