Chapter 15: The Standard Edition IOS

In Depth

The Cisco 1900 and 2820 switches come with two unique IOSs: Standard Edition and Enterprise Edition. The Standard Edition is a character−based IOS, and the Enterprise Edition is similar to the IOS on higher−end routers. The Cisco 3000 series is the only series of switches that comes with a unique IOS; this series offers a graphical user interface (GUI) to configure the switch. In this chapter, we will focus on the setup of the Standard Edition IOS in detail.

The 1900 and 2820 Series Switches

The Catalyst 1900 series switches are Cisco’s entry point into Access layer managed switches. These switches are the only two that work at the Access layer; they can provide up to two 100BaseT or 100BaseFX uplink ports and up to twenty−four 10BaseT ports. The Catalyst 1900 is available in two models: the Standard Edition (SE) and the Enterprise Edition (EE).

The Standard Edition is a low−cost alternative for those migrating from a shared hub environment to a smaller workgroup environment. These switches were specifically designed to be plug−and−play right out of the box with no manual configuration. The Catalyst 1900 SE has 12 or 24 fixed 10BaseT ports with 2 high−speed 100BaseT, or one 100BaseT and one 100BaseFX ports. The Catalyst 1900 switch can be configured using the console port, its Web interface, or Cisco’s Visual Switch Manager. Included in the Standard Edition is support for Domain Name Service (DNS) and Dynamic Host Control Protocol (DHCP) to help with ease of host management. The Standard Edition can be upgraded via the Flash to the Enterprise Edition.

The Enterprise Edition offers the features of the Standard Edition but also provides several high−end solutions. These include Fast EtherChannel, support for Dynamic Inter−Switch Link (DISL), an IOS Command Line Interface (CLI), and support for Cisco Group Management Protocol (CGMP).

The Catalyst 2820 series switch architecture is virtually identical to that of the Cisco Catalyst 1900 series switches. The switch is different because of its height and its uplink bays, which allow for high−speed uplink options such as Fiber Distributed Data Interface (FDDI), Copper Distributed Data Interface (CDDI), 100Mbps, and Asynchronous Transfer Mode (ATM) modules.

In this chapter, we will concentrate on the configuration of the Standard Edition IOS rather than the switch specifications for the 1900 and 2820 series switches.

Note The Catalyst 2820 series routers have been issued an End−of−Life (EOL) notice. This notice means the 2820 is no longer manufactured by Cisco. However, you still need to know how to configure these routers because they still exist in today’s networks.

Now, let’s take a look at the menu−driven interface and how to configure the basics on a Standard Edition IOS on the Cisco Catalyst 1900 and 2820 series.

Main Menu Choices

When you log on to the 1900 switch you are presented with a Main Menu that looks similar to the following:

Catalyst 1900 − Main Menu

[C] Console Settings

[S] System

[N] Network Management

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[P] Port Configuration

[A] Port Addressing

[D] Port Statistics Detail

[M] Monitor

[V] Virtual LAN

[R] Multicast Registration

[F] Firmware

[I] RS−232 Interface

[U] Usage Summaries

[H] Help

[K] Command Line

[X] Exit Management Console

Enter Selection:

The following sections describe the Main Menu options. By typing the letter associated with each command on the Main Menu, you enter that configuration screen.

[C] Console Settings

The following shows the Console Settings menu on the Cisco Catalyst 1900 series:

————————————————————Actions—————————————————

[M] Modify password

[E] Modify secret password

[X] Exit to Main Menu

Enter Selection:

Here is what you’ll see when you select the following settings:

∙[P] Password intrusion threshold—This will limit the number of failed logon attempts and render the Management Console frozen for a predefined amount of time before allowing the next logon. This value may range from 0 to 65500 attempts. If you choose not to use a threshold, you should specify zero.

∙[S] Silent time upon intrusion detection—This is the number of minutes the Management Console will be unavailable for use, due to an excessive number of failed attempts to log on. This value may range from 0 to 65500 minutes. Specify zero only for no silent time.

∙[T] Management Console inactivity timeout—This can be configured to time out a session after a period of inactivity. Once a session has been timed out, the user must log on with a password to continue. The timeout can range from 30 to 65500 seconds. Setting the timeout to zero will indicate to use no timeout.

Tip A non−zero timeout should be set for security reasons.

∙[D] Default mode of status LED—This displays one of three status LEDs: port status, duplex status, and utilization of the switch. You can select the display mode by pressing the mode button on the front panel. Once a mode is selected and the mode button is released, the display automatically returns to the default status after 30 seconds.

∙[M] Modify password—The Management Console password can help prevent unauthorized access. When specifying a password, use a minimum of four characters and a maximum of eight characters.

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The password is case−insensitive and can contain any character with a legal keyboard representation.

∙[E] Modify secret password—The Management Console secret password can help prevent unauthorized access. This password is stored in encrypted form and thus provides enhanced security. When specifying a secret password, use a minimum of 1 character and maximum of 25 characters. The password is case−sensitive and can contain any character with a legal keyboard representation. This password will supersede the regular password.

∙[X] Exit to Main Menu—This option returns you to the Main Menu.

[S]System Menu

You begin configuring the basic system settings by choosing S from the Main Menu. When you do, you’ll see a menu similar to the following:

Let’s look at each of the System Configuration commands. They are listed here with brief explanations:

∙[N] Name of system—In multiple−switch environments, this option aids in determining which switch you are currently configuring. You can use up to 255 characters in the switch name, including spaces.

∙[C] Contact Name—This option defines a contact name in case there are problems with the switch. This field can also contain up to 255 characters. Including a pager number or home contact information as part of the contact name can be helpful.

∙[L] Location—This field can contain up to 255 characters. It provides additional information about where the switch physically resides.

∙[S] Switching Mode—This option allows the switch to be configured for all three switching modes. The three configuration choices are: [1] Store−and− Forward, [2] FragmentFree, and [3] FastForward.

∙[U] Use of store−and−forward for multicast—The switch will always use store−and−forward for broadcasts. This feature allows you to determine which method will be used for multicast frames. You can select from two options: [E] (enabled) allows the switch to use store−and forward for multicast frames, and [D] (disabled; the default) uses the method defined in the Switching Mode option from the System Configuration menu.

∙[A] Action upon address violation—This option gives you three ways to inform the switch what to do when an address violation occurs. The option [S] (suspend) stops the port from forwarding frames of the violation. The option [D] (disable) turns off the port until an administrator disables it. The [I] (ignore) option indicates that no action will be taken.

∙[G] General alert on address violation—This option indicates whether Simple Network Management Protocol (SNMP) trap messages are sent when an address violation occurs.

∙[I] Address aging time—This option defines the number of seconds that dynamic entries will remain in the Media Access Control (MAC) address table. The valid settings are 10 to 1,000,000 seconds. The default is 300 seconds.

∙[P] Network Port—This option specifies the port to which all unknown unicasts are forwarded. You can specify a port in the range of port numbers on the switch: A indicates port 25, B indicates port 26, AUI indicates the AUI port, and N indicates None.

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∙[R] Reset system—This option recycles the power on the switch.

∙[F] Reset to factory defaults—This option clears all configuration settings back to the factory defaults.

Warning If you apply the [F] option, all manual configuration settings will be lost.

∙[B] Broadcast storm control—This option launches the Broadcast Storm menu, which includes five options. (These options are discussed in “Configuring Broadcast Storm Control on Switch Ports” in the Immediate Solutions section.)

∙[X] Exit to Main Menu—This option exits to the Main Menu.

[N]Network Management

By pressing N on the Main Menu, you reach the Network Management menu. This menu can be used to define an IP address for the system, Simple Network Management Protocol (SNMP), Spanning−Tree Protocol (STP), Cisco Discovery Protocol (CDP), and Cisco Group Management Protocol (CGMP).

The following shows the Network Management menu:

Catalyst 1900 − Network Management

[I] IP Configuration

[S] SNMP Management

[B]Bridge − Spanning Tree

[C]Cisco Discovery Protocol

[G]Cisco Group Management Protocol

[H]HTTP Server Configuration

[R] Cluster Management

[X] Exit to Main Menu

Enter Selection:

Let’s look at each option from this menu in more detail.

[I] IP Configuration

Choosing I from the Network Management menu brings up a menu that looks similar to the following:

[X] Exit to previous menu

Enter selection:

In order to use Telnet or SNMP to manage the switch, an IP address must be assigned to the switch. The following are the settings from the IP Configuration menu:

∙[I] IP address—Configures the IP address on the switch.

∙[S] Subnet mask—Configures the switch’s subnet mask.

∙[G] Default gateway—Configures the destination address for the route processor to which the switch will forward unknown or out−of−subnet addresses.

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∙[V] Management VLAN—Allows you to set the VLAN in which you will configure your switch. Cisco recommends that you choose a VLAN other than 1 because all ports are in VLAN1 by default. On the Standard Edition of the IOS software, the available VLANs are 1 through 4. The Enterprise Edition has 64 available VLANs.

∙[X] Exit to previous menu—Exits back to the Network Management menu.

Tip When you change the IP address, the change takes effect immediately. However, all other options from the Network Management menu require a recycling of the power. Configuration changes on the 1900 and 2820 series are automatically saved, but the change can take up to 30 seconds to take effect.

[S] SNMP Management

To make changes to SNMP, choose S from the Network Management menu. The following shows the Network Management (SNMP) Configuration menu options for a CAT 2820:

Catalyst 2820 − Network Management (SNMP) Configuration

————————————————————Settings——————————————————————

————————————————————Actions—————————————————

[X] Exit to previous Menu

Enter selection:

The options available from this menu are as follows:

∙[R] READ community string—Identifies the community that is assigned to the management stations. Those management stations assigned to this community can read the trap messages sent from the switch. You can define a name up to 32 characters; the default is public.

∙[W] WRITE community string—Identifies the community that is assigned to the management stations. Those management stations assigned to this community can read or set SNMP configurations on the switch. You can define a name up to 32 characters; the default is private.

∙WRITE manager IP address—Allows you to define up to four SNMP management stations that can set SNMP configuration parameters on the switch.

∙TRAP—Allows you to define which SNMP management stations can receive TRAP messages on the switch.

∙[U] Authentication Trap generation—Allows you to enable or disable authentication trap message generation.

∙[L] LinkUp/LinkDown trap generation—Informs the switch of the actions to take when the port changes its state from suspended, down, or up from STP. It also notifies the switch when an address violation has occurred, link errors are present, or a manual configuration error had been found.

∙[X] Exit to previous Menu—Takes you back to the Network Management menu.

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SNMP Default Trap Messages

By default, the Cisco Catalyst 1900 and Catalyst 2820 series switches send certain trap messages. Trap messages are sent by default in response to the following events:

∙Port security violations

∙Power recycling (powering on and off)

∙Logon authentication failures

∙STP port changes

∙STP bridge assignments

∙Broadcast threshold problems

∙Power supply problems

[B]Bridge − Spanning Tree

Selecting [B] Bridge − Spanning Tree from the Network Management menu will bring up the following menu. Here we use a 2820 for an example to show a more detailed list of available settings in an upgraded version of the IOS software:

————————————————————Actions——————————————————————

Note Spanning Tree Protocol and its defaults are covered in detail in Chapter 10.

[C] Cisco Discovery Protocol

Choosing C (Cisco Discovery Protocol) from the Network Management menu will bring up the following menu:

Catalyst 1900 − CDP Configuration/Status

——————————Actions————————————

[E] Enable CDP on Port(s) [D] Disable CDP on Port(s) [S] Show Neighbor

[X] Exit to previous menu

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Enter Selection:

The following list shows the commands from the CDP Configuration/Status menu:

∙[H] Hold Time (secs)—Indicates how long a CDP multicast will remain in the CDP table. The valid entries are from 5 to 255 seconds, and the default is 180 seconds.

∙[T] Transmission Interval (secs)—Defines the interval in which the switch will send CDP multicast messages.

∙[E] Enable CDP on Port(s)—Identifies one or more ports on which to enable CDP. You can use the All setting to enable all ports, or you can identify blocks of ports by using a hyphen. For example, to identify ports 1 through 10, enter “1−10”. You can use spaces to separate the variables; so, if you also want ports 12−15, enter “1−10 12−15”.

∙[D] Disable CDP on Port(s)—Identifies one or more ports on which to disable CDP.

∙[S] Show Neighbor—Displays a list of neighboring Cisco devices together with their device ID, MAC address, port, capabilities, and device platform. The device’s capabilities are indicated by letters: R indicates a router, T indicates a Trans Bridge, B indicates a Route Bridge, S indicates a switch, P indicates a repeater, H indicates a host, and I indicates IGMP.

∙[X] Exit to previous menu—Returns you to the Network Management menu.

[G]Cisco Group Management Protocol

You configure Cisco Group Management protocol (CGMP) by selecting G (the last configuration option) on the Network Management menu. In order to function properly, CGMP needs all the ports on the switch to reside in the same VLAN. CGMP allows an intelligent means of limiting multicast flooding to specific ports.

The following shows the menu on a Catalyst 2820 when the G command is chosen from the Network Management menu:

Catalyst 2820 − Cisco Group Management Protocol (CGMP) Configuration

————————————————————Settings——————————————————————

——————————Actions—————————————————————————————————

[L] List IP multicast addresses

[X] Return to previous menu

The following list shows the commands and descriptions for the CGMP Configuration menu:

∙[H] Router hold time (secs)—Indicates the amount of time the switch will keep CGMP multicast information. When the CGMP router fails or the power is recycled, the switch will flood multicast broadcasts out all the ports. The valid range is from 5 to 900 seconds; the default is 5 seconds.

∙[C] CGMP—Enables or disables CGMP on the switch. There are two valid options: E (enabled) and D (disabled; the default).

∙[L] List IP multicast addresses—Lists all multicast addresses learned by CGMP along with the VLAN, source MAC address, and port of the source address.

∙[X] Return to previous menu—Returns you to the Network Management menu.

[P]Port Configuration

From the Main Menu, you can configure each port’s settings from the Port Configuration menu. You must specify a port from Table 15.1.

Table 15.1: The available configurable ports on a Catalyst 2820 from the Port Configuration menu.

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The Port Configuration menu is as follows:

Enter Selection:

The following list shows the options and descriptions for the Port Configuration menu:

∙[D] Description/name of port—This option allows the port name to be changed to a name with 60 characters or less, such as Port to Hanson’s PC.

∙[S] Status of port—This option has two configurable settings: E (enabled) and D (disabled). The default setting places all ports in the enabled mode.

Port Statuses

Although the administrator has only two configurable settings under the Status Of Port option, the port can be in any of the following statuses:

∙Enabled—The port is available to send and receive data frames.

∙Disabled−mgmt—The port has been manually disabled.

∙Suspended−linkbeat—The port cannot detect a link at the other end of the cable. Possibly the cable has become unplugged, the device on the other end is turned off, or the port is not configured on the far−end device.

∙Suspended−jabber—The port is temporarily disabled because of excessive jabber or indecipherable data frames.

∙Suspended−violation—The port has been temporarily disabled because of an address violation. The port is automatically re−enabled once it discontinues receiving invalid source address information.

∙Suspended−ring down—The port is using Fiber Distributed Data Interface (FDDI) links and cannot detect an attached FDDI ring.

∙Suspended−Spanning−Tree−Protocol—The port is not participating in any STP forwarding state.

∙Suspended−not−present—A module in an expansion slot (on the 2820 series only) cannot be detected.

∙Suspended−not−recognized—The switch cannot detect the switch port or a module in the expansion slot (on the 2820 series only).

∙Disabled−self−test—The port has been disabled due to a self−test failure.

∙Disabled−violation—The port has been disabled due to an address violation. When a port is in this state it must manually be reset and enabled.

∙Reset—The port has been manually reset and enabled.

∙[A] Port addressing—This option is used to access the Port Addressing menu.

∙[V] View port settings—This option is used to display individual port statistics.

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∙[N] Next port—This option is used to forward to the next configurable port.

∙[G] Goto port—This option is used to configure any identified port.

∙[P] Previous port—This option is used to configure the previous configurable port.

∙[X] Exit to Main Menu—This option returns you to the Main Menu.

Let’s take a look at the options available on the 2820 using an FDDI module on port A1:

Catalyst 2820 − Port A1 Configuration (Left Slot)

Enter Selection:

The following list shows the menu options and an explanation of each:

∙[M] Module status—This feature has three options. To see the status of the module, use the S option; the other two choices let you either enable or disable the module.

∙[I] Port priority (spanning tree)—This option sets the port priority for the STP root port. The lower the number, the higher the priority. The valid range is from 0 to 255; the default is 128.

∙[C] Path cost (spanning tree)—This option sets the path cost used to choose the STP root port.

∙[H] Port fast mode—PortFast is an option that allows a port to immediately go into forwarding mode. This option offers two settings: E (enable) and D (disable). (The option is explained in detail in Chapter 10.)

∙[L] Novell SNAP frame translation—This option determines whether manual or automatic frame−translation is used by IPX.

∙[U] Unmatched SNAP frame destination—This option identifies the translation of frames for which the frame type cannot be determined. To use this option, option L should be set to automatic.

∙[R] Reset module—This option resets the expansion modules.

∙[F] Reset to factory defaults—This option resets the expansion modules’ configuration to the factory defaults.

∙[1] Basic FDDI settings—This option allows you to see the first expansion module’s status and current configuration.

∙[2] Secondary FDDI settings—This option displays the second screen of the expansion module’s status and current configuration.

∙[A] Port addressing—This option is used to access the Port Addressing menu.

∙[V] View port settings—This option is used to display an individual port’s statistics.

∙[N] Next port—This option is used to forward to the next configurable port.

∙[G] Goto port—This option is used to configure any identified port.

∙[P] Previous port—This option is used to configure the previous configurable port.

∙[X] Exit to Main Menu—This option returns you to the Main Menu.

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