Cisco Catalyst LAN Switching

One of the benefits of the Native IOS Mode is that it implements most of the Layer 2 features found in XDI/CatOS platforms such as the Catalyst 5000. Fortunately, the IOS command-line interface (CLI) has been enhanced to include much of the information previously only found under XDI/CatOS. This section briefly displays and discusses some of the more important enhancements.

Probably the most important enhancement involves the interface range command. Without this feature, it would be necessary to individually configure hundreds of ports in a fully populated switch. Fortunately, this feature allows you to configure multiple interfaces at the same time as shown in Example 18-24.

Example 18-24 Configuring EIGRP as a Routing Protocol

NativeMode(config)# interface range 5/1-5, 6/1-24, 7/1-48 NativeMode(config-if)# switchport mode access NativeMode(config-if)# switchport access vlan 2 NativeMode(config-if)# end NativeMode#

This assigns 77 ports to VLAN 2 in one step, a huge time saver! In short, Example 18-24 is equivalent to the set vlan 2 5/1-5,6/1-24,7/1-48 command on XDI/CatOS-based Catalysts. Notice that interface range commands do not directly appear in the configuration. Instead, the results of Example 18-24 will appear in the output of show running-config on each of the separate 77 interfaces it references.

Tip

Be sure to use the interface range command when configuring Native IOS Mode devices.

Users accustomed to the show port and show trunk XDI/CatOS commands will find familiar ground in the enhancements to the show interface syntax. For example, the XDI/CatOS command show trunk has been ported to the show interface trunk command as shown in Example 18-25.

Example 18-25 The show interface trunk Command

NativeMode# show interfaces trunk Port Mode Encapsulation Status Native vlan Fa5/6 on 802.1q trunking 1 Port Vlans allowed on trunk Fa5/6 1-1005 Port Vlans allowed and active in management domain Fa5/6 1-1005 Port Vlans in Spanning Tree forwarding state and not pruned Fa5/6 none NativeMode#

Many of the show port XDI/CatOS commands have also been ported. For example, Example 18-26 displays information on counters with the show interface counters command.

Example 18-26 The show interface counters Command

NativeMode# show interfaces counters module 1 Port InOctets InUcastPkts InMcastPkts InBcastPkts Gi1/1 1093847 284764 5739 8576 Gi1/2 0 0 0 0 Port OutOctets OutUcastPkts OutMcastPkts OutBcastPkts Gi1/1 876643 198578 4657 7765 Gi1/2 0 0 0 0 NativeMode#

Notice that Example 18-26 uses the module module-number argument to filter the output to only show information for module 1. This option exists on most of the new switching-oriented show interface commands.

Tip

Also use the powerful Output Modifier feature introduced in IOS 12.0. Simply terminate any show command with a pipe symbol (|) and specify a pattern to match (regular expressions are supported!). There are options to include and exclude lines (including an option to output all text found after the first match). The slash (/) key can also be used to search for text.

Example 18-27 displays the output of the errors option to show interfaces counters.

Example 18-27 The show interfaces counters errors Command

NativeMode# show interfaces counters errors module 1 Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize Gi1/1 0 0 0 0 0 Gi1/2 0 0 0 0 0 Port Single-Col Multi-Col Late-Col Excess-Col Carri-Sen Runts Giants Gi1/1 0 0 0 0 0 0 0 Gi1/2 0 0 0 0 0 0 0 NativeMode#

The show interfaces counters trunk command can be used to show the number of frames transmitted and received on trunk ports. Encapsulation errors are also included (use this information to check for ISL/802.1Q encapsulation mismatches).

The show vlan command has also been ported to the Native IOS Mode. In fact, as shown in Example 18-28, it is almost identical to the XDI/CatOS version of this command.

Example 18-28 The show vlan Command

NativeMode# show vlan VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa5/6 2 Martketing active Fa5/1, Fa5/2, Fa5/3, Fa5/6 3 Engineering active Fa5/5, Fa5/6 1002 fddi-default active Fa5/6 1003 token-ring-default active Fa5/6 1004 fddinet-default active Fa5/6 1005 trnet-default active Fa5/6 VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2 ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------ 1 enet 100001 1500 - - - - - 0 0 2 enet 100002 1500 - - - - - 0 0 3 enet 100003 1500 - - - - - 0 0 1002 fddi 101002 1500 - 0 - - - 0 0 1003 tr 101003 1500 - 0 - - srb 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0 NativeMode#