Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for Configuring IPX Multilayer Switching
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 Route Switch Module (RSM) or an external router, see the
Catalyst 5000 Series Software Configuration Guide or the Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide.
IPX MLS must be enabled on the router. The minimal configuration steps are described in the
How to Configure IPX MLS section in this module. For more details on configuring IPX routing, see the "Configuring Novell IPX" module of the
Cisco IOS Novell IPX Configuration Guide.
Restrictions for Configuring IPX Multilayer Switching
This section describes the following restrictions and guidelines:
You must configure the Catalyst 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 offloading 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 Restrictions and Guidelines
When using an external router, use the following guidelines:
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 FDDI), but connect the external router and the switch only through standard 10/100 Ethernet interfaces, ISL, or IEEE 802.1Q links.
Access List 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
You can translate input access lists to output access lists to provide the same effect on the interface.
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.
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).
Maximum Transmission Unit Size Restrictions
In IPX, the two endpoints of communication negotiate the maximum transmission unit (MTU) to be used. MTU size is limited by media type.
Information About IPX Multilayer Switching
The IPX MLS feature provides high-performance, hardware-based, Layer 3 switching for LAN switches. IPX data packet flows are switched between networks, off loading processor-intensive packet routing from network routers.
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 RIP, Enhanced IGRP, 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 conceptual information about IPX Multilayer Switching, see the "Multilayer Switching Overview" module.
How to Configure IPX MLS
To configure one or more routers for IPX MLS, perform the tasks described in the following sections. The number of tasks you perform depends on your particular configuration.
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
mlsrpipx or
mlsrpmanagement-interfacecommand. 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 theTroubleshooting Tips for Configuring IPX MLS section in this module and either the
Catalyst 5000 Series Software Configuration Guide or the
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide.
Before You Begin
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
showmlsrpvtp-domainEXEC command at the switch Console> prompt.
To assign an MLS interface to a specific VTP domain on the MLS-RP, complete the following steps.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfacetypenumber
4.mlsrpvtp-domaindomain-name
5.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfacetypenumber
Example:
Router(config)# interface fastethernet 2/0.1
Selects an interface and enters interface configuration mode.
Enter the interface type and interface number.
Step 4
mlsrpvtp-domaindomain-name
Example:
Router(config-if)# mls rp vtp-domain Engineering
Adds an IPX MLS interface to a VTP domain.
Enter the domain name.
Step 5
end
Example:
Router(config-if)# end
Exits interface configuration mode.
Enabling Multilayer Switching Protocol (MLSP) on the Router
To enable MLSP on the router, complete the following steps.
SUMMARY STEPS
1.enable
2.configureterminal
3.mlsrpipx
4.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
mlsrpipx
Example:
Router(config)# mls rp ipx
Globally enables MLSP on the router. MLSP is the protocol that runs between the MLS-SE and MLS-RP.
Step 4
end
Example:
Router(config)# end
Exits global configuration mode.
Assigning a VLAN ID 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, complete the following steps.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfacetypenumber
4.mlsrpvlan-idvlan-id-number
5.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfacetypenumber
Example:
Router(config)# interface fastethernet2/0.1
Selects an interface and enters interface configuration mode.
Enter the interface type and interface number.
Step 4
mlsrpvlan-idvlan-id-number
Example:
Router(config-if)# mls rp vlan-id 23
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.
Enter the VLAN number.
Step 5
end
Example:
Router(config-if)# end
Exits interface configuration mode.
Enabling IPX MLS on a Router Interface
To enable IPX MLS on a router interface, complete the following steps.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfacetypenumber
4.mlsrpipx
5.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfacetypenumber
Example:
Router(config)# interface fastethernet2/0.1
Selects an interface and enters interface configuration mode.
Enter the interface type and interface number.
Step 4
mlsrpipx
Example:
Router(config-if)# mls rp ipx
Enables a router interface for IPX MLS.
Step 5
end
Example:
Router(config-if)# end
Exits interface configuration mode.
Specifying a Router Interface As a Management Interface
To specify a router interface as the management interface, complete the following steps.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfacetypenumber
4.mlsrpmanagement-interface
5.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfacetypenumber
Example:
Router(config)# interface fastethernet 2/0.1
Configures an interface and enters interface configuration mode.
Enter the interface type and interface number.
Step 4
mlsrpmanagement-interface
Example:
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.
Step 5
end
Example:
Router(config-if)# end
Exits interface configuration mode.
Verifying IPX MLS on the Router
To verify that you have correctly installed IPX MLS on the router, complete the following steps:
SUMMARY STEPS
1.
Enter the showmlsrpipxEXEC command.
2.
Examine the output to learn if the VLANs are enabled.
3.
Examine the output to learn if the switches are listed by MAC address, indicating they are recognized by the MLS-RP.
DETAILED STEPS
Step 1
Enter the showmlsrpipxEXEC 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.
Monitoring and Maintaining IPX MLS on the Router
To monitor and maintain IPX MLS on the router, use one or more of the following commands.
SUMMARY STEPS
1.enable
2.mlsrplocateipx
3.showmlsrpinterfacetypenumber
4.showmlsrpipx
5.showmlsrpvtp-domaindomain-name
6.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
mlsrplocateipx
Example:
Router# mls rp locate ipx
Displays information about all switches currently shortcutting for the specified IPX flow(s).
Step 3
showmlsrpinterfacetypenumber
Example:
Router# show mls rp interface fastethernet 2/0.1
Displays MLS details for a specific interface.
Enter the interface type and interface number.
Step 4
showmlsrpipx
Example:
Router# show mls rp ipx
Displays details for all IPX MLS interfaces on the router, such as 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.
MLSP-ID used in MLSP messages.
List of interfaces in all VTP domains enabled for MLS.
Step 5
showmlsrpvtp-domaindomain-name
Example:
Router# show mls rp vtp-domain engineering
Displays details about IPX MLS interfaces for a specific VTP domain.
Enter the domain name.
Step 6
end
Example:
Router# end
Exits privileged EXEC mode.
Troubleshooting Tips for Configuring IPX MLS
If you entered either the mlsrpipx command or the mlsrpmanagement-interface command on the interface before assigning it to a 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, complete the following steps.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfacetypenumber
4.nomlsrpipx
5.nomlsrpmanagement-interface
6.nomlsrpvtp-domaindomain-name
7.mlsrpvtp-domaindomain-name
8.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfacetypenumber
Example:
Router(config)# interface fastethernet 2/0.1
Configures an interface and enters interface configuration mode.
Enter the interface type and interface number.
Step 4
nomlsrpipx
Example:
Router(config-if)# no mls rp ipx
Disables MLS IPX on a router interface.
Step 5
nomlsrpmanagement-interface
Example:
Router(config-if)# no mls rp management-interface
Removes an interface as the management interface.
Step 6
nomlsrpvtp-domaindomain-name
Example:
Router(config-if)# no mls rp vtp-domain Engineering
The figure below shows an IPX MLS network topology consisting of
three Catalyst 5000 series switches and a Cisco 7505 router--all interconnected
with ISL trunk links.
Figure 1
Example Network: IPX MLS with Cisco 7505 over ISL
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 MLS-RP 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 VTP
server, is a Catalyst 5509 switch with Supervisor Engine III and the NFFC II.
Switch B and Switch C are
VTP client Catalyst 5505 switches.
Operation Before IPX MLS Example
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 After IPX MLS Example
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 Example
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 Configuration Example
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 Example
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)
MLS-RP Configuration Example
This example shows how to configure the MLS-RP:
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
This example shows how to configure 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 10.5.5.155 255.255.255.0
ipx network 2121
mls rp vtp-domain Engineering
mls rp management-interface
mls rp ip
mls rp ipx
!
interface Vlan22
ip address 10.2.2.155 255.255.255.0
ipx network 2222
mls rp vtp-domain Engineering
mls rp ip
mls rp ipx
!
.
.
.
end
Router# show run
Building configuration...
Current configuration:
!
version 12.0
!
interface Vlan22
ip address 10.2.2.155 255.255.255.0
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
Additional References
The following sections provide references related to configuring IPX multilayer switching.
Related Documents
Related Topic
Document Title
IP LAN switching commands: complete command syntax, command mode, defaults, usage guidelines, and examples
Cisco IOS LAN Switching Services Command Reference
No new or modified RFCs are supported by this feature, and support for existing standards has not been modified by this feature.
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Description
Link
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.
To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.
Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1
Feature Information for Configuring IPX MLS
Feature Name
Releases
Feature Information
This table is intentionally left blank because no features were introduced or modified in Cisco IOS Release 12.2(1) or later. This table will be updated when feature information is added to this module.
--
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Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL:
www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.