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Table of Contents

Configuring Ethernet, Fast Ethernet, and Gigabit Ethernet Switching

Configuring Ethernet, Fast Ethernet, and Gigabit Ethernet Switching

This chapter describes how to use the command-line interface (CLI) to configure Ethernet, Fast Ethernet, and Gigabit Ethernet switching on the Catalyst 5000 series switches. The configuration tasks in this chapter apply to Ethernet, Fast Ethernet, and Gigabit Ethernet switching modules, as well as to the Fast Ethernet and Gigabit Ethernet uplink ports on the supervisor engine modules.


Note For complete information on installing Catalyst 5000 series Ethernet, Fast Ethernet, and Gigabit Ethernet modules, refer to the Catalyst 5000 Series Module Installation Guide.

Note For complete syntax and usage information for the commands used in this chapter, refer to the Catalyst  5000 Series Command Reference publication.

This chapter consists of these sections:

Understanding How Ethernet Works

The Catalyst 5000 series switch supports simultaneous, parallel conversations between Ethernet segments. Switched connections between Ethernet segments last only for the duration of the packet. New connections can be made between different segments for the next packet.

The Catalyst 5000 series switch solves congestion problems caused by high bandwidth devices and a large number of users by assigning each device (for example, a server) to its own 10- or 100-Mbps segment. Because each Ethernet port on the Catalyst 5000 series switch represents a separate Ethernet segment, servers in a properly configured switched environment achieve full access to the bandwidth.

Because the major bottleneck in Ethernet networks is usually due to collisions, an effective solution is full-duplex communication, an option for each port on the Catalyst 5000 series switch (Gigabit Ethernet ports only support full duplex). Normally, Ethernet operates in half-duplex mode, which means that stations can either receive or transmit. In full-duplex mode, two stations can transmit and receive at the same time. When packets can flow in both directions simultaneously, effective Ethernet bandwidth doubles from 10 Mbps to 20 Mbps for 10BaseT ports and to 200 Mbps for Fast Ethernet ports.

Switching Frames Between Segments

Each Ethernet port on the Catalyst 5000 series switch can connect to a single workstation or server, or to a hub through which workstations or servers connect to the network.

Ports on a typical Ethernet hub all connect to a common backplane within the hub, and the bandwidth of the network is shared by all devices attached to the hub. If two stations establish a session that uses a significant level of bandwidth, the network performance of all other stations attached to the hub is degraded.

To reduce degradation, the Catalyst 5000 series switch treats each port as an individual segment. When stations on different ports need to communicate, the Catalyst 5000 series switch forwards frames from one port to the other at wire speed to ensure that each session receives the full bandwidth available.

To switch frames between ports efficiently, the Catalyst 5000 series switch maintains an address table. When a frame enters the Catalyst 5000 series switch, it associates the Media Access Control (MAC) address of the sending station with the port on which it was received.

Building the Address Table

The Catalyst  5000 series switch builds the address table by using the source address of the frames received. When the switch receives a frame for a destination address not yet listed in its address table, it floods the frame to all ports of the same virtual LAN (VLAN) except the port that received the frame. When the destination station replies, the switch adds its relevant source address and port ID to the address table. The Catalyst  5000 series switch then forwards subsequent frames to a single port without flooding to all ports.

The address table can store at least 16,000 address entries without flooding any entries. The Catalyst  5000 series switch uses an aging mechanism, defined by a configurable aging timer, so if an address remains inactive for a specified number of seconds, it is removed from the address table.

Default Ethernet, Fast Ethernet, and Gigabit Ethernet Configuration

Table 4-1 shows the Ethernet, Fast Ethernet, and Gigabit Ethernet default configuration.


Table 4-1: Ethernet, Fast Ethernet, and Gigabit Ethernet Default Configuration
Feature Default Value

Port enable state

All ports are enabled

Port name

None

Port priority

Normal

Duplex mode

  • Half duplex for 10-Mbps Ethernet ports

  • Autonegotiate speed and duplex for 10/100-Mbps Fast Ethernet ports

  • Autonegotiate duplex for 100-Mbps Fast Ethernet ports

  • Full duplex for 1000-Mbps Gigabit Ethernet ports

Flow control (Gigabit Ethernet only)

Flow control set to off for receive (Rx) and desired for transmit (Tx)

Link negotiation protocol (Gigabit Ethernet only)

Enabled

Spanning-Tree Protocol

Enabled for VLAN 1

Native VLAN

VLAN 1

Port VLAN cost

  • Port VLAN cost of 100 for 10-Mbps Ethernet ports

  • Port VLAN cost of 19 for 10/100-Mbps Fast Ethernet ports

  • Port VLAN cost of 19 for 100-Mbps Fast Ethernet ports

  • Port VLAN cost of 4 for 1000-Mbps Gigabit Ethernet ports

Fast EtherChannel

Disabled on all Fast Ethernet ports (auto mode)

Setting the Port Configuration

These sections describe how to configure Ethernet, Fast Ethernet, and Gigabit Ethernet switching ports on the Catalyst  5000 series switches:

Setting the Port Name

You can assign names to the ports on Ethernet, Fast Ethernet, and Gigabit Ethernet modules to facilitate switch administration.

To assign a name to a port, perform this task in privileged mode:
Task Command

Step 1 Assign a name to a port.

set port name mod_num/port_num [name_string]

Step 2 Verify that the port name is configured.

show port [mod_num[/port_num]]

This example shows how to set the name for ports 1/1 and 1/2 and how to verify that the port names are configured correctly:

Console> (enable) set port name 1/1 Router Connection
Port 1/1 name set.
Console> (enable) set port name 1/2 Server Link
Port 1/2 name set.
Console> (enable) show port 1
Port  Name               Status     Vlan       Level  Duplex Speed Type
----- ------------------ ---------- ---------- ------ ------ ----- ------------
 1/1  Router Connection  connected  trunk      normal   half   100 100BaseTX
 1/2  Server Link        connected  trunk      normal   half   100 100BaseTX
<...output truncated...>
Last-Time-Cleared
--------------------------
Tue Jun 16 1998, 16:25:57
Console> (enable)

Setting the Port Priority Level

You can configure the priority level of each port. When ports request access to the switching bus simultaneously, the Catalyst 5000 series switch uses the port priority level to determine the order in which ports are given access.

To set the port priority level, perform this task in privileged mode:
Task Command

Step 1 Configure the priority level for a port.

set port level mod_num/port_num {normal  |  high}

Step 2 Verify that the port priority level is configured correctly.

show port [mod_num[/port_num]]

This example shows how to set the port priority level to high for port 1/1 and verify that the port priority is configured correctly:

Console> (enable) set port level 1/1 high
Port 1/1 level set to high.
Console> (enable) show port 1
Port  Name               Status     Vlan       Level  Duplex Speed Type
----- ------------------ ---------- ---------- ------ ------ ----- ------------
 1/1  Router Connection  connected  trunk      high     half   100 100BaseTX
 1/2  Server Link        connected  trunk      normal   half   100 100BaseTX
<...output truncated...>
Last-Time-Cleared
--------------------------
Tue Jun 16 1998, 16:25:57
Console> (enable)

Setting the Port Speed

You can configure the port speed on 10/100-Mbps Fast Ethernet modules. Use the auto keyword to have the port autonegotiate speed and duplex mode with the neighboring port.

Caution Make sure the device on the other end of the link is also configured for autonegotiation or a port speed or duplex mismatch might result.

Note If the port speed is set to auto on a 10/100-Mbps Fast Ethernet port, both speed and duplex are autonegotiated.

To set the port speed for a 10/100-Mbps port, perform this task in privileged mode:
Task Command

Step 1 Set the port speed of a 10/100-Mbps Fast Ethernet port.

set port speed mod  num/port  num {10  |  100 | auto}

Step 2 Verify that the speed of the port is configured correctly.

show port [mod_num[/port_num]]

This example shows how to set the port speed to 100 Mbps on port 2/2:

Console> (enable) set port speed 2/2 100
Port 2/2 speed set to 100 Mbps.
Console> (enable)

This example shows how to make port 2/1 autonegotiate speed and duplex with the neighbor port:

Console> (enable) set port speed 2/1 auto
Port 2/1 speed set to auto-sensing mode.
Console> (enable)

Setting the Port Duplex Mode

You can set the port duplex mode to full or half duplex for Ethernet and Fast Ethernet ports.


Note Gigabit Ethernet ports (including the Gigabit uplink ports on the Supervisor Engine III modules) support full duplex only. You cannot change the duplex mode on these ports.

Note If the port speed is set to auto on a 10/100-Mbps Fast Ethernet port, both speed and duplex are autonegotiated. You cannot change the duplex mode of ports configured for autonegotiation. For information on enabling and disabling autonegotiation on 10/100 Fast Ethernet ports, see the
"Setting the Port Speed" section.

To set the duplex mode of a port, perform this task in privileged mode:
Task Command

Step 1 Set the duplex mode of a port.

set port duplex mod  num/port  num  {full  |  half}

Step 2 Verify that the duplex mode of the port is configured correctly.

show port [mod_num[/port_num]]

This example shows how to set the duplex mode to half duplex on port 2/1:

Console> (enable) set port duplex 2/1 half
Port 2/1 set to half-duplex.
Console> (enable)

Checking Connectivity

Use the ping and traceroute commands to test connectivity out Ethernet, Fast Ethernet, or Gigabit Ethernet ports.

To check connectivity out a port, perform this task in privileged mode:
Task Command

Step 1 Ping a remote host that is located out the port you want to test.

ping [-s] host [packet_size] [packet_count]

Step 2 Trace the hop-by-hop route of packets from the switch to a remote host located out the port you want to test.

traceroute host

Step 3 If the host is unresponsive, check the IP address and default gateway configured on the switch.

show interface
show ip route

This example shows how to ping a remote host and how to trace the hop-by-hop path of packets through the network using traceroute:

Console> (enable) ping somehost
somehost is alive
Console> (enable) traceroute somehost
traceroute to somehost.company.com (10.1.2.3), 30 hops max, 40 byte packets
 1 engineering-1.company.com (173.31.192.206) 2 ms 1 ms 1 ms
 2 engineering-2.company.com (173.31.196.204) 2 ms 3 ms 2 ms
 3 gateway_a.company.com (173.16.1.201) 6 ms 3 ms 3 ms
 4 somehost.company.com (10.1.2.3) 3 ms * 2 ms
Console> (enable)

Configuring the Gigabit Ethernet Modules

This section describes configuration information that is specific to the Catalyst 5000 series Gigabit Ethernet modules. The information in this section applies to the following hardware:


Note For information on configuring Gigabit EtherChannel on the Gigabit EtherChannel module (WS-X5410), refer to the "Configuring Fast EtherChannel and Gigabit EtherChannel" section.

These sections describe how to configure the Catalyst 5000 series Gigabit Ethernet modules:

Gigabit Ethernet Module Port Restrictions

Depending on the Catalyst 5000 series switch model, the supervisor engine model, and the slot placement of the Gigabit Ethernet module in the chassis, not all module ports may be active. Table 4-2 shows which ports on the three-port Gigabit Ethernet module (WS-X5403) are active when the module is installed in a Catalyst 5000 series switch.


Table 4-2: Three-Port Gigabit Ethernet Module (WS-X5403) Slot Restrictions
Switch Gigabit Ethernet Switching Module Port Restrictions

Catalyst 5002

Port 1 is active. Ports 2 and 3 are inactive.

Catalyst 5000

Port 1 is active. Ports 2 and 3 are inactive.

Catalyst 5505

With Supervisor Engine III:
In slots 2 through 3---Port 1 on bus A, port 2 on bus B, and port 3 on bus C.
In slot 4---Port 1 on bus B, port 2 on bus A, and port 3 on bus C.
In slot 5---Port 1 on bus C, port 2 on bus B, and port 3 on bus A.

With Supervisor Engine II:
Any slot---Port 1 is active. Ports 2 and 3 are inactive.

Catalyst 5509

With Supervisor Engine III:
Any slot---All ports are active.

With Supervisor Engine II:
Any slot---Port 1 is active. Ports 2 and 3 are inactive.

Catalyst 5500

With Supervisor Engine III:
In slots 2 through 5---Port 1 on bus A, port 2 on bus B, and port 3 on bus C.
In slots 6 through 8---Port 1 on bus B; ports 2 and 3 are inactive.
In slots 9 through 12---Module cannot be inserted due to physical limitations.

With Supervisor Engine II:
In slots 2 through 8---Port 1 on bus B; ports 2 and 3 are inactive.
In slots 9 through 12---Module cannot be inserted due to physical limitations.

Table 4-3 lists the Catalyst 5000 series switch slot assignment restrictions for the Gigabit EtherChannel switching module.


Table 4-3: Gigabit EtherChannel Switching Module (WS-X5410) Slot Restrictions
Switch Number of Modules Allowed1 Slot Restrictions

Catalyst 5000 switch

2

Slots 3 through 5: Installing a Gigabit EtherChannel switching module in slots 3 through 5 provides a 1.2-Gb connection to the switch backplane.

Catalyst 5505 switch

2

Slots 3 through 5: Installing a Gigabit EtherChannel switching module in slots 3 through 5 provides three 1.2-Gb connections to the switch backplane2.

Catalyst 5509 switch

4

Slots 3 through 9: Installing the Gigabit EtherChannel switching module in slots 3 through 9 provides three 1.2-Gb connections to the switch backplane2.

Catalyst 5500 switch

3

Slots 3 through 5: Installing a Gigabit EtherChannel switching module in slots 3 through 5 provides three 1.2-Gb connections to the switch backplane2.

Slots 6 through 8: Installing a Gigabit EtherChannel switching module in slots 6 through 8 provides a 1.2-Gb connection to the switch backplane.

Slots 9 through 12: The module is not supported in slots 9 through  12.

1The Gigabit EtherChannel switching module (WS-X5410) occupies two chassis slots.
2In order to utilize all three 1.2-Gb backplane buses, you must have a Supervisor Engine III module installed in slot  1.

Configuring Flow Control on Gigabit Ethernet Ports

All of the Catalyst 5000 series Gigabit Ethernet modules can respond to flow-control frames (pause frames) received from neighboring devices by inhibiting the transmission of packets from each port for a period of time. When a pause frame is received on a port, it is processed internally; pause frames are not switched through the system.

In addition, most Catalyst 5000 series Gigabit Ethernet modules can transmit pause frames to neighboring devices. If the receive buffer for a port becomes full, the module transmits a pause packet on that port that tells remote devices to delay sending more packets for a specified period of time.


Note The nine-port Gigabit EtherChannel module (WS-X5410) never transmits pause frames. However, you might need to configure the module to advertise the ability to send flow-control frames if the attached device refuses to complete negotiation unless it receives such advertisements. For more information on Gigabit Ethernet port negotiation, see the "Configuring Link Negotiation on the Gigabit EtherChannel Module" section.

Use the set port flow control command to configure flow control on Gigabit Ethernet ports. Table 4-4 describes the flow-control behavior of a Gigabit Ethernet port depending on the set port flowcontrol command keywords used to configure the port.


Table 4-4: Gigabit Ethernet Flow-Control Keyword Functions
Keywords Gigabit Ethernet Ports Gigabit EtherChannel Ports (WS-X5410 Only)

receive on

The port uses flow control dictated by the neighbor port.

The port operates with an attached device that is required to send flow-control packets, or with an attached device that is not required to but might send flow-control packets.

receive desired

The port uses flow control if the neighbor port uses it, and does not use flow control if the neighbor port does not use it.

The port operates with an attached device that is required to send flow-control packets, or with an attached device that is not required to but might send flow-control packets.

receive off

The port does not use flow control, regardless of whether flow control is requested by the neighbor port.

The port discards received flow-control frames without processing them. If negotiation is enabled, the port advertises that it refuses to accept flow-control frames. This can cause the remote device not to send flow-control frames, or if the attached device is configured to send flow-control frames unconditionally, it can prevent the link from coming up.

send on

The port sends flow-control frames to the neighbor port.

The local port advertises that it will send flow-control frames.

send desired

The port sends flow-control frames to the neighbor port if the neighbor port asks to use flow control.

The local port advertises that it will send flow-control frames if the attached device elects to receive them.

send off

The port does not send flow-control frames to the neighbor port.

The local port advertises that it will never send flow-control frames.

To configure flow control on a Gigabit Ethernet port, perform this task in privileged mode:
Task Command

Step 1 Set the flow-control parameters on a Gigabit Ethernet port.

set port flowcontrol {receive | send} mod_num/port_num {off | on | desired}

Step 2 Verify the flow-control configuration.

show port flowcontrol

This example shows how to turn transmit and receive flow control on and how to verify the flow-control configuration:

Console> (enable) set port flowcontrol send 3/1 on
Port 3/1 will send flowcontrol to far end.
Console> (enable) set port flowcontrol receive 3/1 on
Port 3/1 will require far end to send flow control
Console> (enable) show port flowcontrol
Port  Send-Flowcontrol  Receive-Flowcntl  RxPause  TxPause
      Admin   Oper      Admin   Oper
----- ----------------  ----------------  -------  -------
 3/1  on      disagree  on      disagree  0        0
 3/2  off     off       off     off       0        0
 3/3  desired on        desired off       10       10
Console> (enable)

Configuring Link Negotiation on the Gigabit EtherChannel Module

Caution Unlike autonegotiation with 10/100 Fast Ethernet, Gigabit Ethernet autonegotiation does not involve negotiating port speed. You cannot disable autonegotiation using the set port speed command.

With Gigabit Ethernet ports, autonegotiation is used to exchange flow-control parameters, remote fault information, and duplex information (even though Catalyst 5000 series Gigabit Ethernet ports only support full-duplex mode). With Gigabit Ethernet ports, you configure autonegotiation using the set port negotiation command. Gigabit Ethernet port negotiation is enabled by default.

The ports on both ends of a Gigabit Ethernet link must have the same setting. The link will not come up if the ports at each end of the link are set inconsistently (link negotiation enabled on one port and disabled on the other). Table 4-5 shows the four possible autonegotiation configurations for a Gigabit Ethernet link and the resulting link status for each configuration.


Table 4-5: Gigabit Ethernet Autonegotiation Configuration and Possible Link States
Autonegotiation State Link Status
Near End1 Far End2 Near End Far End

Off

Off

Up

Up

On

On

Up

Up

Off

On

Up

Down

On

Off

Down

Up

1Near End refers to the local Gigabit EtherChannel module port.
2Far End refers to the remote port at the other end of the Gigabit link.

To enable link negotiation on a Gigabit Ethernet port, perform this task in privileged mode:
Task Command

Step 1 Enable Gigabit Ethernet link negotiation.

set port negotiation mod_num/port_num enable

Step 2 Verify the link negotiation configuration.

show port negotiation [mod_num/port_num]

This example shows how to enable port negotiation and verify the configuration:

Console> (enable) set port negotiation 5/1 enable
Port 5/1 negotiation enabled.
Console> (enable) show port negotiation 5/1
Port     Link Negotiation
------- --------------------
5/1     enabled
Console> (enable)

To disable link negotiation on a Gigabit Ethernet port, perform this task in privileged mode:
Task Command

Step 1 Disable Gigabit Ethernet link negotiation.

set port negotiation mod_num/port_num disable

Step 2 Verify the link negotiation configuration.

show port negotiation [mod_num/port_num]

Configuring Fast EtherChannel and Gigabit EtherChannel

These sections describe how to configure Fast EtherChannel on Catalyst  5000 series Fast Ethernet ports and Gigabit EtherChannel on Catalyst  5000 series Gigabit  Ethernet ports:

Understanding How Fast EtherChannel and Gigabit EtherChannel Work

Fast EtherChannel provides parallel bandwidth of up to 800  Mbps (400-Mbps full duplex) between a Catalyst  5000 series switch and another switch or host by grouping multiple Fast Ethernet interfaces into a single logical transmission path.

Fast EtherChannel segments must be contiguous ports on a Fast EtherChannel-capable Fast Ethernet switching module. You can configure Fast Ethernet ports into Fast EtherChannel groups containing two or four ports, yielding 400- or 800-Mbps bidirectional bandwidth, respectively.

Gigabit EtherChannel provides parallel bandwidth of up to 8 Gbps (4 Gbps full duplex) between a Catalyst  5000 series switch and another switch or host by grouping multiple Gigabit Ethernet interfaces into a single logical transmission path.

You can configure Gigabit Ethernet ports into Gigabit EtherChannel groups containing two or four ports, yielding 4- or 8-Gbps bidirectional bandwidth.

The Port Aggregation Protocol (PAgP) facilitates the automatic creation of Fast EtherChannel and Gigabit EtherChannel links by exchanging packets between channel-capable ports. The protocol learns the capabilities of port groups dynamically and informs the neighboring ports.

Once PAgP identifies correctly paired channel-capable links, it groups the ports into a channel. The channel is then added to the spanning tree as a single bridge port. Inbound broadcast and multicast packets on one segment in a channel are blocked from returning on any other segment of the channel. Outbound broadcast and multicast packets are sent through only one segment in the channel.

PAgP includes four user-configurable channel modes: on, off, auto, and desirable. Each mode affects the way a port handles PAgP packets. By default, ports are in auto mode. Table 4-6 describes each mode.


Table 4-6: Channel Modes
Mode Description

on

Forces the port to channel without negotiation.

off

Prevents the port from channeling.

auto

Places a port into a passive negotiating state, in which the port responds to PAgP packets it receives but does not initiate PAgP packet negotiation. (Default)

desirable

Places a port into an active negotiating state, in which the port initiates negotiations with other ports by sending PAgP packets.

Both the auto and desirable modes allow ports to negotiate with connected ports to determine if they can form a channel, based on criteria such as port speed, trunking state, native VLAN, and so on.

Channel ports can be in different channel modes as long as the modes are compatible. For instance, a port in desirable mode can form a channel successfully with another port that is in desirable or auto mode. Similarly, a port in auto mode can form a channel with another port in desirable mode. However, a port in auto mode cannot form a channel with another port that is also in auto mode, since neither port will initiate negotiation.

If a segment within a channel fails, traffic previously carried over the failed link switches to the remaining segments within the channel. A trap is sent upon a failure identifying the switch, the channel, and the failed link.

Channels are configured using the standard CLI or Simple Network Management Protocol (SNMP).

Hardware Support for Fast EtherChannel and Gigabit EtherChannel

Only the Catalyst 5000 series Gigabit EtherChannel switching module (WS-X5410) supports Gigabit EtherChannel.

Table 4-7 shows the Catalyst 5000 series hardware that supports Fast EtherChannel.


Table 4-7: Fast EtherChannel Hardware Support
Fast EtherChannel-Capable Hardware Product Numbers

Supervisor Engine II modules, dual-port

WS-X5505
WS-X5506
WS-X5509
WS-X5530

Supervisor Engine III 10/100 Fast Ethernet uplink modules, dual-port

WS-U5531-FETX
WS-U5533-FEFX-MMF
WS-U5535-FEFX-SMF

Supervisor Engine III 10/100 Fast Ethernet uplink module, 4-port

WS-U5537-FETX

10/100BaseTX Fast EtherChannel switching module, 12-port

WS-X5203

100BaseFX Fast EtherChannel switching module, 12-port

WS-X5201

100BaseFX Backbone Fast EtherChannel switching module, 12-port

WS-X5201R

10/100BaseTX Backbone Fast EtherChannel switching module, 24-port

WS-X5225R

Fast and Gigabit EtherChannel Configuration Guidelines and Restrictions

These sections describe restrictions that apply and guidelines to follow when configuring Fast or Gigabit EtherChannel on the Catalyst 5000 series switches:

EtherChannel Configuration Guidelines

If improperly configured, some Fast EtherChannel or Gigabit EtherChannel ports are disabled automatically to avoid network loops and other problems. Use the following guidelines to avoid configuration problems:

Fast EtherChannel Configuration Restrictions

On all Fast EtherChannel-capable hardware, port groups determine which ports can form a channel. Channels must be composed of contiguous ports from the same port group. A channel cannot have some ports from one group and some ports from another. However, you can configure multiple channels within a single group.

Ports on the Fast EtherChannel-capable modules are grouped as follows:

The Supervisor Engine II modules and the Supervisor Engine III dual-port uplink modules support a single Fast EtherChannel configuration: one two-port channel.

On the other modules, each group of four ports can be channeled in any the following ways:

Figure 4-1 shows valid and invalid Fast EtherChannel (and Gigabit EtherChannel) configurations.


Figure 4-1: Valid and Invalid Fast and Gigabit EtherChannel Configurations


Gigabit EtherChannel Configuration Restrictions

The ports on the nine-port Gigabit EtherChannel Switching Module (WS-X5410) form two groups of four ports each (ports 1-4 and 5-8). Port 9 cannot be channeled. A Gigabit EtherChannel must be composed of contiguous ports from the same group. A channel cannot have some ports from one group and some ports from another.

Each group of four ports can be channeled in any the following ways:

Figure 4-1 shows valid and invalid Gigabit EtherChannel (and Fast EtherChannel) configurations.

Configuring Fast EtherChannel and Gigabit EtherChannel

To configure a Fast EtherChannel or Gigabit EtherChannel bundle, perform this task in privileged mode:
Task Command

Step 1 Make sure that the ports you want to channel are configured correctly. (Refer to the "Fast and Gigabit EtherChannel Configuration Guidelines and Restrictions" section.)

Step 2 Ensure a loop-free topology for all channeled VLANs1.

Step 3 Create a channel on the desired ports.

set port channel port_list {on | off | auto | desirable}

Step 4 Verify the channeling configuration.

show port channel [mod_num[/port_num]] [info | statistics]

1Gigabit EtherChannel only.

This example shows how to create a two-port Fast EtherChannel and verify the configuration:

Console> (enable) set port channel 1/1-2 on
Port(s) 1/1-2 channel mode set to on.
Console> (enable) 06/30/1998,17:09:32:PAGP-5:Port 1/1 left bridge port 1/1.
06/30/1998,17:09:32:PAGP-5:Port 1/2 left bridge port 1/2.
06/30/1998,17:09:33:PAGP-5:Port 1/1 joined bridge port 1/1-2.
06/30/1998,17:09:33:PAGP-5:Port 1/2 joined bridge port 1/1-2.
Console> (enable) show port channel
Port  Status     Channel   Channel     Neighbor                  Neighbor
                 mode      status      device                    port
----- ---------- --------- ----------- ------------------------- ---------- 
 1/1  connected  on        channel     WS-C2926    007475320     1/1       
 1/2  connected  on        channel     WS-C2926    007475320     1/2       
----- ---------- --------- ----------- ------------------------- ---------- 
Console> (enable)

To remove a Fast EtherChannel or Gigabit EtherChannel bundle, perform this task in privileged mode:
Task Command

Step 1 Remove an Ethernet channel.

set port channel port_list off

Step 2 Verify the configuration.

show port channel [mod_num[/port_num]] [info | statistics]

This example shows how to disable a channel and how to verify the configuration:

Console> (enable) set port channel 1/1-2 off
Port(s) 1/1-2 channel mode set to off.
Console> (enable) show port channel
No ports channelling
Console> (enable)

Using Protocol Filtering

These sections describe how to configure protocol filtering on Catalyst  5000 series Ethernet VLANs and on Ethernet, Fast Ethernet, and Gigabit Ethernet ports:

Understanding How Protocol Filtering Works

A Supervisor Engine III that has a NetFlow Feature Card (NFFC) or NFFC II can support protocol filtering within port VLANs.

Protocol filtering is supported only on Ethernet VLANs and on nontrunking Ethernet, Fast Ethernet, and Gigabit Ethernet ports. Protocol filtering is disabled by default on all Ethernet VLANs. In addition to assigning a VLAN to a port, you can configure the port to be a member of one or more protocol groups. Trunking ports are always members of all protocol groups. Filtering is not performed on trunk ports; therefore, there are no interoperability issues with switches without an NFFC. Layer 2 protocols, such as Spanning-Tree Protocol (STP) and Cisco Discovery Protocol (CDP), are not affected by protocol filtering.

With an NFFC or NFFC II installed, the supervisor engine software supports autolearning. With autolearning, ports become members of the protocol flood domain only after receiving packets of the corresponding protocol. For example, if a host supports both IP and Internetwork Packet Exchange (IPX) and the host is using only IP, the port to which the host is connected is configured as auto for IPX. The port does not receive any IPX flood traffic. When the host actually sends an IPX packet, it is detected by the supervisor, and the port is added to the IPX group, which allows the port to start receiving the IPX flood traffic.

Dynamic ports and ports that have port security enabled are members of all protocol groups.

You can configure a port with any one of these modes for a particular protocol: on, off, or auto. If the configuration is set to on, the port receives all the flood traffic for that protocol. If the configuration is set to off, the port does not receive any flood traffic for that protocol. If the configuration is set to auto, the port is added to the group only after receiving packets of the specific protocol.

By default, ports are configured to on for the IP protocol group. You can configure the ports to auto for IP if only clients are connected to the ports. The default port configuration for IPX and Group is auto. Autoconfigured ports are removed from the protocol group if no packets are received for that protocol within 60 minutes. Ports are also removed from the protocol group when the supervisor detects a link down.

An NFFC or NFFC II provides broadcast and unicast flood traffic filtering based on the port's membership to different protocol groups in addition to the port VLAN. The NFFC and NFFC II do not process Token Ring packets.

With protocol filtering enabled, ports are grouped on a protocol basis. The NFFC and NFFC II classify packets into the following four protocol groups:

A port can be a member of one or more of the first three groups.

Configuring Protocol Filtering

To configure protocol filtering on Ethernet, Fast Ethernet, or Gigabit Ethernet ports, perform this task in privileged mode:
Task Command

Step 1 Enable protocol filtering on the switch.

set protocolfilter enable

Step 2 Set the protocol membership of the desired ports.

set port protocol mod_num/port_num {ip | ipx | group} {on | off | auto}

Step 3 Verify the port filtering configuration.

show port protocol [mod_num[/port_num]]

This example shows how to enable protocol filtering, set the protocol membership of ports, and verify the configuration:

Console> (enable) set protocolfilter enable
Protocol filtering enabled on this switch.
Console> (enable) set port protocol 2/1 ip off
IP protocol disabled on port 2/1.
Console> (enable) set port protocol 5/1 ip auto
IP protocol set to auto mode on module 5/1.
Console> (enable) show port protocol 1/1-2
Port	 Vlan	      IP	    IP Hosts  	IPX	      IPX Hosts	   Group   Group Hosts
-----	----------	------	----------	---------	------------	--------	----------------
1/1	  1         	on	       10	    auto-on   	4           	auto-off	 0
1/2  trunking	  on        	-    	on        	-	           on	       -
Console> (enable)

To disable protocol filtering, perform this task in privileged mode:
Task Command

Disable protocol filtering on the switch.

set protocolfilter disable

Ethernet Switching Configuration Examples

Figure 4-2 shows an example Ethernet configuration for a single Catalyst  5000 series switch. This example shows all devices on each module as either full duplex or half duplex. However, you can configure each port on each module independently for either full- or half-duplex operation. In addition, this example shows a direct correlation between port speed and traffic priority, although the two parameters are completely independent.


Note A Catalyst 5000 switch is used in this example, but the configuration can apply to all Catalyst  5000 series switches.

Figure 4-2: Single Catalyst 5000 Series Switch Configuration


The example configuration shown in Figure 4-2 is based on the following assumptions:

This example shows how to configure Ethernet on a Catalyst 5000 series switch:

Step 1 Configure a name for the port by entering the set port name command. You see this display:

Step 2 Configure the priority level for the port by entering the set port level command. You see this display:

Step 3 Configure the speed for the port by entering the set port speed command. You see this display:

Step 4 Configure the duplex mode for the port (half or full duplex) by entering the set port duplex command. You see this display:

Step 5 To verify the Ethernet configuration, enter the show port command. After entering this command, you see a display similar to the verification example in the "Setting the Port Name" section.


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