Table Of Contents
Basic System Configuration Page
Entering Basic Configuration Parameters
Entering a New Password or Changing the Password
Using the Switch Image to Monitor the Switch
Using Telnet to Connect to the Switch
Enabling and Disabling a Fixed Port
Displaying the Current State of a Fixed Port
Changing the Duplex Mode of a Fixed Port
Enabling and Disabling Flooded Traffic
Enhanced Congestion Control on 100-Mbps Ports
Displaying the Detailed Port Statistics Reports
Adding and Deleting Dynamic Addresses
Adding and Deleting Permanent Unicast Addresses
Adding and Deleting Permanent Multicast Addresses
Defining the Maximum Secure Address Count
Entering the SNMP Community Strings
Enabling and Disabling Trap Generation
Defining Trap Manager Settings
Defining Write Manager Settings
Enabling and Disabling Spanning-Tree Protocol
Spanning-Tree Operating Parameters
Changing Spanning-Tree Configurations for the Bridge
Changing Spanning-Tree Parameters for a Port
Listing and Displaying Neighboring Devices
Console and Upgrade Configuration Page
Displaying the Exception Statistics Report
Displaying the Utilization Statistics Report
Deleting and Changing the Password to the Switch
Configuring Broadcast Storm Control
Modifying the Router Hold Time
Listing IP Multicast Addresses
Web-Based Management
This chapter describes how to use the web console, a GUI for changing the switch configuration and monitoring switch activity. This chapter includes instructions for the most common configuration tasks.
Before continuing with this chapter, you should have read the information in the "Overview of the Web Console" section.
Basic System Configuration Page
To display the (Figure 4-1), click Home on the action bar. You can also display this page by entering the IP address or domain name server of the switch in the URL field, as described in the "Assigning IP Information to the Switch" section. This page acts as the home page for the switch web console.
Use this page to:
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Specify basic information about the switch
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Figure 4-1 Basic System Configuration Page
Entering Basic Configuration Parameters
To operate the switch with its default settings, an IP address must first be assigned to the switch. The IP address is assigned from the [I] option on the . The following information (used by network management applications to identify the switch on a network topology map) is also typically assigned but not required.
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Entering a New Password or Changing the Password
A switch password is optional. Follow these steps to enter a password:
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If a password has already been defined, enter the password at the prompt when you first access the switch using the web console. The is redisplayed only after you enter the correct password.
If the Authorization Failed. Retry? message appears, check that you are using the correct password, and reenter it.
If you have forgotten the password, see the "Recovering from a Lost or Forgotten Password" section.
For information about changing the password, see the "Deleting and Changing the Password to the Switch" section.
Using the Switch Image to Monitor the Switch
This page has an image of the switch that reflects the activity of the LEDs on the switch front panel at the last poll interval. Generally, a green LED means proper functioning, and amber means a problem or malfunction. When an LED is off, the switch or a function is inactive. For information about using the LEDs and the Mode button to monitor the switch, see the "LEDs and Mode Button" section.
Using Telnet to Connect to the Switch
Click the Telnet hotlink to display the .
Connecting to Cisco Resources
If you need assistance from Cisco, the following resources are available:
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Port Management Page
To display the (Figure 4-2), click Port on the action bar, or click the port image on the . Use this page to:
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Figure 4-2 Port Management Page
Enabling and Disabling a Fixed Port
To enable or disable a port, select or deselect the check box in the Status column, and click Apply. The default is Enabled (check box is selected).
To confirm the action, click Home on the action bar to display the switch image. The port LED for a disabled port is amber.
Displaying the Current State of a Fixed Port
The current state of each fixed port is shown in the grayed-out field in the Status column. Port status is a system-wide indicator of the state of a port. Security violations, management intervention, or actions of the Spanning-Tree Protocol can change the port status. Each port is always in one of the states listed in :
Changing the Duplex Mode of a Fixed Port
Select the duplex mode from the drop-down menu in the Duplex Mode column for the port, and click Apply. The default setting for the 10BaseT ports is half duplex. The default for 100BaseTX ports is autonegotiation-enabled. The default for the 100BaseFX port is half duplex.
Full-duplex operation is simultaneous transmission of data in both directions across a link. For example, 10BaseTX ports operating in full-duplex mode can provide up to 20 Mbps of bandwidth across the switched link. You can use full-duplex connections (either 10 Mbps or 100 Mbps) to enhance transmission speeds between other switches or routers that support full-duplex operation. A likely full-duplex scenario would be to connect a 100BaseT port to a server with a 100BaseT adapter configured for full-duplex operation.
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To confirm your changes, follow these steps:
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If you cannot confirm the actions you requested, return to the and make the changes again.
Enabling and Disabling Flooded Traffic
To enable flooding, select the unicast and multicast check boxes for the port, and click Apply. To disable flooding, deselect these check boxes for the port, and click Apply.
By default, the switch forwards to all ports (floods) unicast and multicast packets with unknown MAC addresses. As there are some configurations where this flooding is unnecessary, you can disable the flooding of unicast and multicast packets on a per-port basis. To control flooding, the switch forwards, floods, and filters packets in accordance with the IEEE 802.1d specification.
The switch forwards each packet according to the source address stored in the switch address table that matches the destination address of the packet. If the port a packet is received on has both the packet source and destination addresses on it, the packet is filtered (not forwarded).
If the switch cannot match a destination address of a packet with a source address in its address table, the switch floods the packet with the unknown destination address to all ports. Broadcast packets are always flooded to all ports.
For example, when the switch receives a unicast packet with a destination address that it has not learned, the default is to flood it to all ports. On ports with only statically assigned addresses or single stations attached, there are no unknown destinations and flooding would serve no purpose. In this case, you can disable flooding on a per-port basis.
In another example, when the switch receives a multicast packet, you can use the or SNMP to register multicast addresses and specify to which ports these packets are to be forwarded. You can also disable the normal flooding of unregistered multicast packets on a per-port basis. Besides reducing unnecessary traffic, these features open up the possibility of using multicast packets for dedicated groupcast applications such as broadcast video.
The switch also supports source-port filtering. This enhanced filtering capability only forwards packets to destinations when they are received on specified ports. These destinations are referred to as restricted static addresses. You can assign restricted static address from the .
Enhanced Congestion Control on 100-Mbps Ports
Enhanced congestion control (ECC) helps reduce congestion in the switch and helps keep the switch from dropping frames due to full transmit queues. The default is Disabled.
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Displaying the Detailed Port Statistics Reports
To display the (Figure 4-3) report on a particular port, click Stats... for that port.
Detailed Port Statistics Page
To display the (), click Stats... from the . Use this page to display the receive and transmit port statistics and to help identify performance or connectivity problems, which are indicated under the Errors heading.
Figure 4-3 Detailed Port Statistics Page
describes the error headings on the page.
Address Table Management Page
To display the (see Figure 4-4), click Address on the action bar. Use this page to manage the address tables that the switch uses to forward traffic between ports. The address tables list the destination MAC address and the port number. You can also specify how a port filters and forwards unmatched unicast addresses and nonregistered multicast addresses. Although multicast address registrations are configured elsewhere, you can use this menu to specify additional source-port filtering on the multicast addresses.
Figure 4-4 Address Table Management Page
Flooding is the forwarding of unicast and multicast packets with unknown destination addresses to all ports. In certain applications, flooding might be unnecessary and undesirable. To control flooding, the switch forwards, floods, and filters packets in accordance with the IEEE 802.1d specification.
The switch forwards each packet according to the source address stored in the switch address table that matches the destination address of the packet. If the port a packet is received on has both the packet source and destination addresses on it, the packet is filtered (not forwarded).
If the switch cannot match a destination address of a packet with a source address in its address table, the switch floods the packet with the unknown destination address to all ports. Broadcast packets are always flooded to all ports.
For example, when the switch receives a unicast packet with a destination address that it has not learned, the default is to flood it to all ports. On ports with only statically assigned addresses or single stations attached, there are no unknown destinations and flooding would serve no purpose. In this case, you can disable flooding on a per-port basis.
In another example, when the switch receives a multicast packet, you can use the or SNMP to register multicast addresses and specify to which ports these packets are to be forwarded. You can also disable the normal flooding of unregistered multicast packets on a per-port basis. Besides reducing unnecessary traffic, these features open up the possibility of using multicast packets for dedicated groupcast applications such as broadcast video.
The switch also supports source-port filtering. This enhanced filtering capability only forwards packets to destinations when they are received on specified ports. These destinations are referred to as restricted static addresses. You can assign restricted static (permanent) addresses from the .
Adding and Deleting Dynamic Addresses
To define how long addresses that have not been seen should be retained by the switch, specify in the Aging Time field the number of seconds (10 to 1,000,000) after which an unused dynamic address is automatically removed from the list, and click Apply. The default is 300.
To delete an address from the Dynamic Address Table, select the address you want to delete, and click Remove.
Dynamic addresses are source Media Access Control (MAC) addresses that are learned by the switch and then dropped when they are not in use. With multiple MAC address support on all ports, you can connect any port on the switch to individual workstations, repeaters, switches, routers, or other network devices. The switch provides dynamic addressing by learning the source address of each packet it receives on each port and adding the address and its associated port number to the address table. As stations are added or removed from the network, the switch updates the address table, adding new entries and aging out those that are currently not in use.
You can manually enter addresses into the address table, including static addresses. Because static addresses do not age, you must manually remove them. Static addressing also allows for a measure of security in that access to a port can be restricted. See the "Port Security Table Page" section for more information.
Adding and Deleting Permanent Unicast Addresses
To add an address to the table, select the port from the scroll list, specify the MAC address of that port in the MAC Address field, and click Add. The address is added immediately to the running (current) configuration and to NVRAM. To delete an address from the table, select the address you want to delete, and click Remove.
The Permanent Unicast Address Table contains addresses that an administrator has specifically assigned to certain ports. Unlike dynamic addresses, these addresses are not aged-out. When addressing security is enabled on a port, the permanent addresses statically assigned by an administrator (and possibly other addresses that are sticky-learned) determine which hosts can connect to a port. Sticky-learned addresses are learned and made permanent by the switch.
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Adding and Deleting Permanent Multicast Addresses
To register an address, select the port from the scroll list, enter the MAC address of that port in the MAC Address field, and click Register. To delete an address from the table, select the address you want to delete, and click Unregister.
The Permanent Multicast Address Table lists the registered multicast addresses that have been assigned to each port on the switch.
Port Security Table Page
To display the (Figure 4-5), click Port Security Table from the . Use this page to enable port security on a port and to define the size of the address table for secured ports.
Limiting the number of devices that can connect to a secure port can have the following advantages:
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The following fields validate port security or indicate security violations:
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Figure 4-5 Port Security Table Page
Securing a Port
To enable port security on a port, select the check box in the Security column, and click Apply. The default is Disabled (check box is not selected).
On the following web console pages, you can specify the action the switch takes when packets with unauthorized addresses arrive on the port.
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Defining the Maximum Secure Address Count
A secure port can have from 1 to 132 secure addresses associated with it. Setting the address table to have one address ensures the attached device has the full bandwidth of the port.
Enter a number from 1 to 132 in the Maximum Secure Addresses column, and click Apply.
Secured ports restrict the use of a port to a user-defined group of stations. When you assign static addresses to a secure port, the switch does not forward any packets with source addresses outside that group. If you define the address table of a secure port to contain only one address, the workstation or server attached to that port is guaranteed the full bandwidth of the port.
The number of devices on a secured port can range from 1 to 132. The addresses for the devices on a secure port are statically assigned by an administrator or sticky-learned. Sticky-learning takes place when the address table for a secured port does not contain a full complement of static addresses. The port sticky-learns the source address of incoming packets and automatically assigns them as static addresses.
Secured ports generate address-security violations under the following conditions:
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When a security violation occurs, the port can be suspended or disabled. When a port is disabled, you must manually reenable the port. When a port is suspended, it is reenabled when a packet containing a valid address is received. You can also choose to ignore the violation and keep the port enabled. You can define the action taken by the switch either by using the or by using the MIB objects.
SNMP Management Page
To display the (see Figure 4-6), click SNMP on the action bar. Use this page to perform the following tasks:
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Figure 4-6 SNMP Management Page
You can use SNMP management, based on the Catalyst 1900 MIB, to specify management stations authorized to set configuration parameters and to receive traps. Up to four management stations can set MIB objects, and up to three stations can receive traps. If no management station is specified, any SNMP station can set parameters if the correct write community string accompanies the request. However, once a write-manager IP address is defined, only an explicitly specified management station can issue set operations. Once a management station has been assigned, it receives all traps issued by the switch.
Entering the SNMP Community Strings
Community strings serve as passwords for SNMP messages.
To define the SNMP agent read community string, enter up to 32 characters in the Read Community String field, and click Apply. The default is Public.
To define the write community string for the switch, enter up to 32 characters in the Write Community String field, and click Apply. The default is Private.
Enabling and Disabling Trap Generation
To enable or disable trap generation, use the following check boxes, and click Apply.
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The linkUp trap is generated when a port is enabled for any of these reasons:
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The default is Enabled (check box is selected).
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Defining Trap Manager Settings
A trap manager, or trap client, is a management workstation configured to receive and process traps. You can enter up to four trap managers and their accompanying community strings. Enter the IP address or host name and community string in the IP Address/Hostname and Community String fields, and click Add. To delete a manager from the Trap Manager scroll list, select the trap manager, and click Remove.
A trap manager community string can contain 32 characters. You can specify the IP address for the trap manager in dotted quad format (nnn.nnn.nnn.nnn). You can specify the name of the trap manager if the switch is connected to a domain name server.
Continue with further definitions for the second, third, and fourth traps, as needed.
For more information about traps, see the "Using FTP to Access the MIB Files" section.
Defining Write Manager Settings
Up to four IP addresses or host names of stations can issue write requests to the switch. Enter the IP address or host name of that station in the IP Address/Hostname field, and click Add. To delete a manager from the Write Manager scroll list, select the write manager, and click Remove.
Spanning-Tree Management Page
To display the (), click STP on the action bar. Use this page to change parameters for the Spanning-Tree Protocol (STP), an industry standard for avoiding loops in switched networks. The first part of the page displays the current spanning-tree operating parameter values received from the root bridge, spanning-tree settings for the current root switch, and the settings this switch is to use when it becomes the root switch. The second part of this page is used to define port-level parameters.
Figure 4-7 Spanning-Tree Management Page
Enabling and Disabling Spanning-Tree Protocol
Spanning-Tree Protocol is enabled by default (check box is selected). To disable Spanning-Tree Protocol, deselect Enable Spanning Tree, and click Apply.
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Spanning-Tree Operating Parameters
The following parameters are read-only and could be defined on another switch.
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Changing Spanning-Tree Configurations for the Bridge
To change the spanning-tree parameters that this switch would use as the root switch, change the following parameters, and click Apply.
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Changing Spanning-Tree Parameters for a Port
To change the spanning-tree parameters for a port, change the following parameters, and click Apply.
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CDP Management Page
To display the (see Figure 4-8), click CDP on the action bar. Use this page to enable CDP for the switch, set the global CDP parameters, and display information about neighboring devices.
Cisco Discovery Protocol (CDP) is a device-discovery protocol that the switch uses to maintain information about neighboring devices. Network-management applications that support CDP can then use this information to discover those devices. By gathering information about the types of devices in the network, the links between those devices, and the number of interfaces within each device, CDP enables network management applications to display a topological map of the network. Detailed information about the connections between devices is also available.
Figure 4-8 CDP Management Page
Listing and Displaying Neighboring Devices
The CDP Neighbors list shows the devices with which this switch is exchanging CDP messages.
To browse a specific neighbor from the web console, the neighbor must be a device that has web-console support. Select the neighbor from the scroll list, and click Browse.
To Telnet to a neighbor, the neighbor must have Telnet support. Select the neighbor from the scroll list, and click Telnet.
To display detailed information about a neighbor, select it from the scroll list, and click Details....
Setting CDP Options
In the Packet Hold Time field, specify the number of seconds (5 to 255) that the switch keeps the CDP neighbor information, and click Apply. The default is 180.
In the Packet Transmission Time field, specify the number of seconds (5 to 900) between CDP messages, and click Apply. The default is 60.
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Enabling CDP on Ports
To enable CDP on one or more ports, select the port from the CDP Disabled scroll list, and click Enable.
There can be times when you do not want CDP to exchange information with certain devices. In this case, disable the port with the devices attached to it. To disable CDP on a port, select the port you want to delete from the CDP Enabled scroll list, and click Disable.
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SPAN Configuration Page
To display the (Figure 4-9), click SPAN on the action bar. Use this page to do the following:
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Frame capturing cannot take place until all three of these parameters have been set.
You can route a copy of incoming and outgoing port traffic to a monitor port for analysis and troubleshooting. When a port is selected as the monitor port, it sends out only traffic seen on the ports defined in the port capture list.
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Figure 4-9 SPAN Configuration Page
You can monitor traffic on a given port by forwarding incoming and outgoing traffic on the port to another port. Any port can be defined as the monitor port, and any combination of ports can be monitored.
To enable port monitoring, change the following parameters, and click Apply.
To enable frame capturing on the monitoring port, select the Capturing frames to the Monitor check box, and click Apply. The default is Disabled (check box is not selected).
Select the port to which captured frames are to be sent, and click Apply. The default is None.
To select ports to be monitored, select the port listed in the Ports Not Monitored scroll list, and click Add to move to the ports to the Ports Monitored scroll list.
To remove ports from the Ports Monitored scroll list, select the ports you want to remove from the Ports Monitored scroll list, and then click Remove.
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Console and Upgrade Configuration Page
To display the (Figure 4-10), click Console on the action bar. Use this page to set the console port parameters and to upgrade the switch firmware.
Figure 4-10 Console and Upgrade Configuration Page
Configuring the Console Port
After connecting the console port of the switch to a management station or modem, set the following default characteristics of the console port to match the characteristics of the management station or modem, and click Apply.
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Set the following parameters to define the call features, and click Apply:
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Upgrading the Switch Firmware
The Switch Version field displays the firmware version currently used by the switch. You can download the latest switch firmware from a TFTP server or from a TFTP client.
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1 minute. The switch then resets and begins using the new firmware.To download the switch firmware from a TFTP server, follow these steps:
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To download the switch firmware from a TFTP client, follow these steps:
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Statistics Reports Page
To display the (), click Statistics on the action bar. Use this page to reset the statistics of all ports and to display the summary exception and utilization statistics.
Figure 4-11 Statistics Reports Page
Resetting Port Statistics
To reset statistics for a port, select the port from the Selected Port scroll list, and click Reset Port Statistics.
To reset the statistics for all ports, click Reset All Statistics.
Displaying the Exception Statistics Report
This report displays the number of receive and transmit errors for each port.
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Displaying the Utilization Statistics Report
This report displays the number of frames received, forwarded, and transmitted for each port.
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System Management Page
To display the (), click System on the action bar. Use this page to define the switch system-wide parameters and configure broadcast storm control.
Figure 4-12 System Management Page
Assigning IP Information
After you set the following IP parameters for the switch, click Apply:
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Assigning Switch Parameters
To improve switch performance and set flood or traffic control, set the following parameters, and click Apply:
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The switch offers the following switching modes:
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If latency is an issue, use FragmentFree switching.
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errors before transmission. In this mode, latency is measured as last-bit-received to first-bit-transmitted or "Last-In, First-Out" (LIFO). This latency does not include the time to receive the entire packet, which can vary, according to packet size. At 100 Mbps, the packet receipt time varies between 51.2 microseconds and 1.2 milliseconds. At 10 Mbps, the packet receipt time varies between 5.12 and 120 microseconds. The store-and-forward mode is always used for broadcast packets and transfers from 10-Mbps to 100-Mbps ports.Store-and-forward is the most error-free form of switching, but the forwarding latency is higher than FragmentFree (cut-through) switching (see ). If you have frame check sequence (FCS) or alignment errors, use the store-and-forward mode so that packets with errors are filtered and not propagated to the rest of the network.
Table 4-3 Switching Latencies
10 Mbps
100 Mbps
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10 MbpsFragmentFree (cut-through)
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Store-and-forward1
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1 Although this table shows store-and-forward experiencing the lowest latency, the figures do not include the time it takes to receive the packet, which varies according to the packet size.
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A unicast address identifies one unique device on the network. However, if the switch has not received packets from the device for a while (longer than the aging period), the switch removes the address from its memory, and the address is then an unknown unicast address. The switch must flood (send to all ports except the one the packet is received on) packets destined for the unknown unicast address in order to ensure the device receives the packet. Once the switch learns the location of the device, this flooding stops.
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When back pressure is enabled and no buffers are available to a port, the switch generates collision frames across the affected port and causes the transmitting station to resend the packets. The switch can then use this retransmission time to clear its receive buffer by transmitting packets already in the queue.
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Deleting and Changing the Password to the Switch
If a password has been defined, and you want to delete it, click Clear Password.
If you want to change the password, click Clear Password. Then, from the (the Home page), follow these steps:
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Configuring Broadcast Storm Control
To inhibit the forwarding of broadcast packets when an excessive number of them arrive from a given port, change the following settings, and click Apply:
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CGMP Management Page
To display the (), click CGMP on the action bar. Use this page to enable Cisco Group Management Protocol (CGMP) and list the IP multicast addresses currently being handled by CGMP.
Figure 4-13 CGMP Management Page
CGMP reduces the unnecessary flooding of IP multicast packets by limiting the transmission of these packets to only the CGMP clients that should receive them. CGMP manages multicast traffic by allowing directed switching of IP multicast traffic within a network. CGMP offers the following benefits:
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CGMP filtering requires a network connection from the switch to a router running CGMP. When CGMP is enabled, it automatically identifies the ports to which the CGMP-capable router is attached. CGMP is enabled by default and supports a maximum of 64 IP multicast group registrations.
For information on IP multicast, including Internet Group Management Protocol (IGMP), refer to RFC 1112.
For additional information about CGMP and multicast addresses, see the "System Management Page" section and the "Address Table Management Page" section.
Enabling CGMP
To enable CGMP, select the check box, and click Apply. The default is Enabled (check box is selected).
Modifying the Router Hold Time
In the Router Hold Time field, specify the number of seconds (5 to 900) the switch waits before removing all IP multicast groups learned from CGMP, and click Apply. The default is 300.
The Router Hold Time field displays the number of seconds (between 5 and 900) the switch waits for keepalive messages before deleting CGMP-learned multicast groups. Multicast routers that support CGMP periodically send CGMP join messages to advertise themselves to switches within a network. A receiving switch saves the information and sets a timer equal to the router hold time. The timer is updated every time the switch receives a CGMP join message advertising itself. When the last CGMP-capable router goes down, the switch discards the multicast-group information from the router.
Listing IP Multicast Addresses
The IP Multicast Address Table lists the IP multicast addresses currently controlled by CGMP and the destination ports that will receive multicast traffic to this address.
