Cisco Knowledge Suite Cisco SystemsCisco Press
   

   
Home
MyCKS
Cutting Edge
Certification
Core Reference
Guided Learning
   
Networking Architecture
LAN
WAN
Switching
Internet Protocols (IP)
Network Protocols
Transport and Application Protocols
Desktop Protocols
Security and Troubleshooting
Network Resources and Management
Integrated Services
 

Configuring LAN Interfaces

   

Contents Next >

Configuring LAN Interfaces

  

 

Configuring an Ethernet or a Fast Ethernet Interface

  

 

Configuring Fast EtherChannel

  

 

Configuring a Fiber Distributed Data Interface

  

 

Configuring a Hub Interface

  

 

Configuring a LAN Extender Interface

  

 

Configuring a Token Ring Interface

  

 

LAN Interface Configuration Examples

Save to MyCKS

 
Cisco IOS 12.0 Interface Configuration

From: Cisco IOS 12.0 Interface Configuration
Author: Technologies Riva; Systems Cisco
Publisher: Cisco Press (53)
More Information

1. Configuring LAN Interfaces

You can use the information in this chapter to configure LAN interfaces supported on Cisco routers and access servers. This chapter describes the processes for configuring LAN interfaces. It contains these sections:

For examples of configuration tasks, see the section “LAN Interface Configuration Examples” at the end of this chapter.

For hardware technical descriptions and information about installing interfaces, refer to the hardware installation and configuration publication for your product. For a complete description of the LAN interface commands used in this chapter, see Chapter 4, “Configuring Interface Commands.” To locate documentation of other commands that appear in this chapter, search online at www.cisco.com.

Configuring an Ethernet or a Fast Ethernet Interface

Cisco supports both 10-Mbps Ethernet and 100-Mbps Fast Ethernet. Support for the 10-Mbps and 100-Mbps Ethernet interface is supplied on various Ethernet network interface cards or systems. The Fast Ethernet NP-1FE module, for example, provides the following benefits:

  • VLAN routing—VLAN support enables network managers to group users logically rather than by physical location. The high performance of the underlying Cisco 4700, combined with the feature-rich NP-1FE, makes it an ideal combination for a low-density, higher-performance application such as inter-VLAN routing.

  • High-speed interconnections—The Fast Ethernet interface enables network managers to implement Fast Ethernet routing solutions for optimal cost and performance across a wide range of applications, including campus or enterprise backbones and data centers. It is also a low-cost way to provide Fast Ethernet access to traditional low-speed WAN services.

  • Local-area network (LAN) aggregation— The Cisco 4500 series or Cisco 4700 series routers can support as many as 12Ethernet, 4 Token Ring, or 1 FDDI segment. ISDN interfaces are also supported.

    With the Catalyst 3000 or Catalyst 5000 system, the Fast Ethernet processor can be used to aggregate up to twelve 10-Mbps LANs and give them high-speed access to such Layer 3 routing services as providing firewalls and maintaining access lists.

Cisco 7200 series routers support a new I/O controller with an RJ-45 interface. The optional Fast Ethernet port is configurable for use at 100-Mbps full-duplex or half-duplex operation (half duplex is the default). The Fast Ethernet port is equipped with either a single MII receptacle or an MII receptacle and an RJ-45 receptacle. To support this new feature, the media-type interface command has been modified. The media-type interface command now supports two options:

  • 100BaseX—Specifies an RJ-45 100BaseX physical connection

  • miiSpecifies a media-independent interface

Second-generation Fast Ethernet Interface Processors (FEIP2-DSW-2TX and FEIP2-DSW-2FX) are available on Cisco 7500 series routers and on Cisco7000 series routers with the 7000 Series Route Switch Processor (RSP7000) and 7000 Series Chassis Interface (RSP7000CI). The FEIP2-DSW is a dual-port, fixed-configuration interface processor that provides two 100-Mbps Fast Ethernet (FE) interfaces. Each interface on the FEIP2-DSW supports half-duplex only for a maximum aggregate bandwidth of 200Mbps.

Use the show interfaces, show controllers mci, and show controllers cbus EXEC commands to display the Ethernet port numbers. These commands provide a report for each interface supported by the router or access server.

Use the show interface fastethernet command to display interface statistics, and use the show controller fastethernet command to display the information about the Fast Ethernet controller chip. The output shows statistics that include information about initialization block information, transmit ring, receive ring, and errors.

For information on how to configure Fast EtherChannel, refer to the tasks listed in the “Configuring Fast EtherChannel” section in this chapter.

Ethernet and Fast Ethernet Interface Configuration Task List

You perform the tasks in the following sections to configure features on an Ethernet or Fast Ethernet interface (the task in the first section is required; the remaining tasks are optional):

Specifying an Ethernet or a Fast Ethernet Interface

To specify an Ethernet interface and enter interface configuration mode, use one of the following commands in global configuration mode:

Command

Purpose

interface ethernet number

Begins interface configuration.

interface ethernet slot/port

Begins interface configuration for the Cisco 7200 series and 7500 series routers.

interface ethernet slot/port-adapter/port

Begins interface configuration for Cisco 7500 series routers.

interface fastethernet number

Begins interface configuration for the Cisco 4000 series routers with a Fast Ethernet NIM installed.

interface fastethernet slot/port

Specifies a Fast Ethernet interface and enters interface configuration mode on the Cisco 7200 series routers.

interface fastethernet slot/port-adapter/port

Specifies a Fast Ethernet interface and enters interface configuration mode on the Cisco 7500 series routers.

Use the show interfaces fastethernet command to display the Fast Ethernet slots and ports. The Fast Ethernet NIM and the FEIP default to half-duplex mode.

Specifying an Ethernet Encapsulation Method

Currently, there are three common Ethernet encapsulation methods:

  • The standard ARPA Ethernet Version 2.0 encapsulation, which uses a 16-bit protocol type code (the default encapsulation method)

  • SAP IEEE 802.3 encapsulation, in which the type code becomes the frame length for the IEEE802.2 LLC encapsulation (destination and source service access points, and a control byte)

  • The SNAP method, as specified in RFC 1042, which allows Ethernet protocols to run on IEEE802.2 media

The encapsulation method you use depends upon the routing protocol you are using, the type of Ethernet media connected to the router or access server, and the routing or bridging application you configure.

Establish Ethernet encapsulation of IP packets by using one of the following commands in interface configuration mode:

Command

Purpose

encapsulation arpa

Selects ARPA Ethernet encapsulation.

encapsulation sap

Selects SAP Ethernet encapsulation.

encapsulation snap

Selects SNAP Ethernet encapsulation.

For an example of selecting Ethernet encapsulation for IP, see the section “Enabling Ethernet Encapsulation Example” later in this chapter.

Specifying Full-Duplex Operation

The default is half-duplex mode on the FEIP2-DSW-2FX. To enable full-duplex mode on the FEIP2-DSW-2FX (for a maximum aggregate bandwidth of 200 Mbps), use one of the following commands in interface configuration mode:

Command

Purpose

full-duplex

or

no half-duplex

Enables full-duplex on the Fast Ethernet interface of the FEIP2-DSW-2FX.

For an example of how to enable full-duplex mode on Fast Ethernet, see the section “Enabling Full-Duplex Operation Example” later in this chapter.

CAUTION

To prevent system problems, do not configure both FEIP2-DSW-2FX interfaces for full-duplex operation at the same time.

NOTE

The FEIP2-DSW-2TX supports half-duplex only, and should not be configured for full-duplex.

Specifying the Media and Connector Type

You can specify that the Ethernet network interface module (NIM) on the Cisco4000 series routers use either the default of an AUI and a 15-pin connector or 10BaseT and an RJ-45 connector. To do so, use one of the following commands in interface configuration mode:

Command

Purpose

media-type aui

Selects a 15-pin Ethernet connector.

media-type 10baset

Selects an RJ-45 Ethernet connector.

The default media connector type is an RJ-45 or SC (fiber-optic) connector. You can specify that the interface use either an MII connector or an RJ-45 or SC (fiber-optic) connector (this is the default). To do so, use one of the following commands in interface configuration mode:

Command

Purpose

media-type mii

Selects an MII Ethernet connector.

media-type 100BaseX

Selects an RJ-45 Ethernet connector for the FEIP2-DSW-2TX or an SC connector for the FEIP2-DSW-2FX.

NOTE

When using the I/O controller that is equipped with an MII receptacle and an RJ-45 receptacle, only one receptacle can be configured for use at a time.

Extending the 10BaseT Capability

On Cisco 4000 series or Cisco 4500 series routers, you can extend the twisted-pair 10BaseT capability beyond the standard 100 meters by reducing the squelch (signal cutoff time). This feature applies only to the LANCE controller 10BaseT interfaces. LANCE is the AMD controller chip for the Cisco 4000 and Cisco 4500 Ethernet interface.

NOTE

This does not apply to the FastEthernet interface.

To reduce squelch, use the first command that follows in interface configuration mode. You can later restore the squelch by using the second command.

Command

Purpose

squelch reduced

Reduces the squelch.

squelch normal

Returns squelch to normal.

Configuring Fast Ethernet 100BaseT

You must configure the Fast Ethernet 100BaseT interface on a Cisco AS5300 so that it can be recognized as a device on the Ethernet LAN. The Fast Ethernet interface supports 10-and 100-Mbps speeds with the 100BaseT and 10BaseT routers, hubs, and switches.

To configure the interface, use the following commands, beginning in privileged EXEC mode:

Step

Command

Purpose

1

configure terminal

Enters global configuration mode.

2

interface fastethernet number

Enters Fast Ethernet interface configuration mode.

3

ip address address subnet-mask

Assigns an IP address and subnet mask to the interface.

4

speed {10 | 100 | auto}

Assigns a speed to the interface. The default is 100Mbps1.

5

duplex {full | half | auto}

Sets up the duplex configuration on the Fast Ethernet interface. The default is half duplex.3

  1. The auto option automatically negotiates the speed based on the speed and the peer router, hub, or switch media.

To use the autonegotiation capability (that is, to detect speed and duplex modes automatically), you must set both speed and duplex to auto. Setting the speed to autonegotiates speed only, and setting duplex to autonegotiates duplex only. Table 1-1 describes the access server's performance for different combinations of the duplex and speed command options. The specified duplex command option plus the specified speed command option produces the resulting system action.

Table 1-1. The Relationship Between Duplex and Speed Command Options

Duplex Command

Speed Command

Resulting System Actions

duplex auto

speed auto

Autonegotiates both speed and duplex modes.

duplex auto

speed 100 or speed 10

Autonegotiates both speed and duplex modes.

duplex half or duplex full

speed auto

Autonegotiates both speed and duplex modes.

duplex half

speed 10

Forces 10 Mbps and half duplex.

duplex full

speed 10

Forces 10 Mbps and full duplex.

duplex half

speed 100

Forces 100 Mbps and half duplex.

duplex full

speed 100

Forces 100 Mbps and full duplex.

Configuring the PA-12E/2FE Port Adapter

The PA-12E/2FE Ethernet switch port adapter provides Cisco7200 series routers with up to 12 10-Mbps and 2 10/100-Mbps switched Ethernet (10BaseT) and Fast Ethernet (100BaseTX) interfaces for an aggregate bandwidth of 435Mbps, full duplex. The PA-12E/2FE port adapter supports the Ethernet, IEEE 802.3, and IEEE 802.3u specifications for 10-Mbps and 100-Mbps transmission over UTP cables.

The PA-12E/2FE port adapter off-loads Layer2 switching from the host CPU by using store-and-forward or cut-through switching technology between interfaces within the same VLAN on the PA-12E/2FE port adapter. The PA-12E/2FE port adapter supports up to four VLANs (bridge groups).

NOTE

The PA-12E/2FE port adapter is a dual-width port adapter, which means it occupies two horizontally aligned port adapter slots when installed in a Cisco7200 series router. (Single-width port adapters occupy individual port adapter slots in a Cisco7200 series router.)

All interfaces on the PA-12E/2FE port adapter support autosensing and autonegotiation of the proper transmission mode (half duplex or full duplex) with an attached device. The first two PA-12E/2FE interfaces (port0 and port1) also support autosensing and autonegotiation of the proper connection speed (10 Mbps or 100 Mbps) with an attached device. If an attached device does not support autosensing and autonegotiation of the proper transmission mode, the PA-12E/2FE interfaces attached to the device automatically enter half-duplex mode. Use the show system:running-config command to determine if a PA-12E/2FE interface is autosensing and autonegotiating the proper transmission mode with an attached device. Use the full-duplex and the half-duplex commands to change the transmission mode of a PA-12E/2FE interface. After changing the transmission mode, use the show interfaces command to verify the interface's transmission mode.

NOTE

If you use the full-duplex and the half-duplex commands to change the transmission mode of the first two PA-12E/2FE interfaces (port0 and port1), the transmission speed of the two PA-12E/2FE interfaces automatically defaults to 100 Mbps. The first two PA-12E/2FE interfaces only operate at 10 Mbps when the interfaces are autosensing and autonegotiating the proper connection speed (10 Mbps or 100 Mbps) with an attached device.

To configure the PA-12E/2FE port adapter, perform the tasks in the following sections (the task in the first section is required; all other tasks are optional):

NOTE

If you plan to use a PA-12E/2FE interface to boot from a network (TFTP), ensure that the interface is configured for a loop-free environment, an IP address is configured for the interface's bridge-group virtual interface, and system boot image 11.2(10)P is installed on your router (use the show version command to view your router's system boot image). Then, before booting from the network server, use the bridge-group bridge-group number spanning-disabled command to disable the Spanning-Tree Protocol configured on the interface to keep the TFTP server from timing out and closing the session.For information on other commands that can be used to configure a PA-12E/2FE port adapter, see Chapter 4, “Configuring Interface Commands.” For PA-12E/2FE port adapter configuration examples, see the “PA-12E/2FE Port Configuration Examples” section later in this chapter.

Configuring the PA-12E/2FE Port Adapter

This section provides instructions for a basic configuration. You might also need to enter other configuration commands, depending on the requirements for your system configuration and the protocols you plan to route on the interface.

To configure the interfaces on the PA-12E/2FE port adapter, use the following commands in global configuration mode:

Step

Command

Purpose

1

bridge bridge-group protocol ieee

Specifies the type of Spanning-Tree Protocol.

The PA-12E/2FE port adapter supports DEC and IEEE Spanning-Tree Protocols; however, Cisco recommends using the IEEE protocol when configuring bridge groups.

2

interface fastethernet slot/port (ports 0 and 1)

interface ethernet slot/port (ports 2 through 13)

Enters the interface you want to configure.

3

bridge-group bridge-group

Assigns a bridge group to the interface.

4

cut-through [receive | transmit]

Optionally, configures the interface for cut-through switching technology. The default is store-and-forward.

5

full-duplex

Optionally, if an attached device does not support autosensing or autonegotiation, it configures the transmission mode for full duplex. The default is half duplex.

6

no shutdown

Changes the shutdown state to up.

7

exit

Returns to configuration mode.

8

 

Repeat steps 1 through 7 for each interface.

9

copy system:running-config nvram:startup-config

Saves the new configuration to memory.

To enable integrated routing and bridging on the bridge groups, use the following commands beginning in global configuration mode:

Step

Command

Purpose

1

bridge irb

Enables integrated routing and bridging.

2

interface bvi bridge-group

Enables a virtual interface on a bridge group.

3

ip address address mask

Assigns an IP address and subnet mask to the bridge-group virtual interface.

4

no shutdown

Changes the shutdown state to up.

5

exit

Returns to configuration mode.

6

 

Repeat steps 1 through 5 for each bridge group.

7

bridge bridge-group route protocol

Specifies the protocol for each bridge group.

8

exit

Exits configuration mode.

9

copy system:running-config nvram:startup-config

Saves the new configuration to memory.

Monitoring and Maintaining the PA-12E/2FE Port Adapter

After configuring the new interface, you can display its status and verify other information. To display information about the PA-12E/2FE port adapter, use the following commands in EXEC mode:

Command

Purpose

show version

Displays the configuration of the system hardware; the software version; the names and sources of configuration files; and the boot image.

show controllers

Displays all current port adapters and their interfaces.

show interface fastethernet slot/port (ports 0 and 1)

or

show interface ethernet slot/port (ports 2 through 13)

Verifies the interfaces have the correct slot number and that the interface and line protocol are in the correct state.

show bridge group

Verifies all bridge groups and their interfaces.

show interface ethernet slot/port irb(ports 2 through 13)

or

show interface fastethernet slot/port irb (ports 0 and 1)

Verifies the correct routed protocol is configured for each interface.

show protocols

Displays the protocols configured for the entire system and specific interfaces.

show pas eswitch addresses fastethernet slot/port(ports 0 and 1)

or

show pas eswitch addresses ethernet slot/port(ports 2 through 13)

Displays the Layer 2 learned addresses for each interface.

more system:running-config

Displays the running configuration file.

more nvram:startup-config

Displays the configuration stored in NVRAM.

Configuring Bridge Groups by Using the 12E/2FE VLAN Configuration WebTool

The 12E/2FE VLAN Configuration WebTool, shown in Figure 1-1, is a Web browser-based Java applet that displays configured interfaces and bridge groups for PA-12E/2FE port adapters installed on Ciscorouters. With the WebTool, you can perform the following tasks:

  • Create and delete bridge groups (also referred to as VLANs)

  • Add and remove PA-12E/2FE interfaces from bridge groups

  • Assign colors to bridge groups and PA-12E/2FE interfaces

  • Administratively shut down (disable) and bring up (enable) PA-12E/2FE interfaces

  • View the bridge-group status of each PA-12E/2FE interface

You can access the 12E/2FE VLAN Configuration WebTool from your router's home page.

Figure 1-1. Sample Home Page for a Cisco 7200 Series Router (Cisco7206 Shown)

NOTE

You must use a Java-enabled Web browser to access the 12E/2FE VLAN Configuration WebTool from your router's home page.

All Cisco routers running Cisco IOS Release 11.0 or later have a home page. If your router has an installed PA-12E/2FE port adapter, you can access the 12E/2FE VLAN Configuration WebTool from the router's home page.

NOTE

All Cisco router home pages are password protected. Contact your network administrator if you do not have the name or password for your Cisco7200 series router.

The VLAN Configuration WebTool hypertext link is listed in the router's home page only when a PA-12E/2FE port adapter is installed in the router.

Configuring the 100VG-AnyLAN Port Adapter

The 100VG-AnyLAN port adapter (PA-100VG) is available on Cisco 7200 series routers and on Cisco7500 series routers.

The PA-100VG provides a single interface compatible with and specified by IEEE 802.12 to support 100Mbps over Category 3 or Category 5 unshielded twisted-pair (UTP) cable with RJ-45 terminators. The PA-100VG supports 802.3 Ethernet packets and can be monitored with the IEEE802.12 Interface MIB.

To configure the PA-100VG port adapter, use the following commands beginning in global configuration mode:

Step

Command

Purpose

1

interface vg-anylan slot/port-adapter/port (Cisco 7500)

or

interface vg-anylan slot/port (Cisco 7200)

Specifies a 100VG-AnyLAN interface and enter interface configuration.

2

ip address ip-address mask

Specifies the IP address and subnet mask to the interface.

3

frame-type ethernet

Configures the frame type. Currently, only Ethernet frames are supported. The frame type defaults to Ethernet.

NOTE

The port number for the 100VG-AnyLAN port adapter is always 0.

Configuring the PA-100VG interface is similar to configuring an Ethernet or Fast Ethernet interface. To display information about the 100VG-AnyLAN port adapter, use the show interfaces vg-anylan EXEC command.

   

Contents Next >

Save to MyCKS

 

Breaking News

One of the primary architects of OpenCable, Michael Adams, explains the key concepts of this initiative in his book OpenCable Architecture.

Expert Advice

Ralph Droms, Ph.D., author of The DHCP Handbook and chair of the IETF Dynamic Host Configuration Working Group, guides you to his top picks for reliable DHCP-related information.

Just Published

Residential Broadband, Second Edition
by George Abe

Introduces the topics surrounding high-speed networks to the home. It is written for anyone seeking a broad-based familiarity with the issues of residential broadband (RBB) including product developers, engineers, network designers, business people, professionals in legal and regulatory positions, and industry analysts.

             
     

From the Brains at InformIT

|

Contact Us

|

Copyright, Terms & Conditions

|

Privacy Policy

 

© Copyright 2000 InformIT. All rights reserved.