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Configuring Cisco Catalyst

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en  (to enable)
then enter passwork


You can create VLANs in either VLAN database mode or global configuration mode. You must create VLANs that are numbered higher than 1005 in global configuration mode. And the VTP mode must be set to transparent in order to create these VLANs. VLANs that are numbered higher than 1005 are not advertised by VTP. Furthermore, VLANs that are numbered higher than 1005 are stored in the switch configuration file and not in the VLAN .dat file. The default location of the VLAN .dat file in Catalyst 4000 Switches with Supervisor Engine IV is the cat4000_flash directory.

    Switch#dir cat4000_flash:

    Directory of cat4000_flash:/

    1 -rw- 676 <no date> vlan.dat

    524260 bytes total (523584 bytes free)


The show vtp status command shows the VTP information in the switch.

    Switch#show vtp status

    VTP Version : 2
    Configuration Revision : 0
    Maximum VLANs supported locally : 1005
    Number of existing VLANs : 8
    VTP Operating Mode : Server
    VTP Domain Name : cisco
    VTP Pruning Mode : Enabled
    VTP V2 Mode : Disabled
    VTP Traps Generation : Disabled
    MD5 digest : 0xA4 0x18 0x78 0x52 0x5A 0x1B 0x2E 0x14
    Configuration last modified by at 5-28-01 05:17:02
    Local updater ID is on interface Vl1 (lowest numbered VLAN interface)



      Issue the show vlan command in order to check the VLAN information.

          Switch#show vlan

          VLAN Name                             Status    Ports
          ---- -------------------------------- --------- -------------------------------
          1    default                          active    Gi1/1, Gi1/2, Gi3/1, Gi3/2
                                                          Gi3/3, Gi3/4, Gi3/5, Gi3/6
                                                          Gi3/7, Gi3/8, Gi3/9, Gi3/10
                                                          Gi3/11, Gi3/12, Gi3/13, Gi3/14
                                                          Gi3/15, Gi3/16, Gi3/17, Gi3/18

          !--- Output suppressed.

          VLAN Name                             Status    Ports
          ---- -------------------------------- --------- -------------------------------
          1002 fddi-default                     act/unsup
          1003 token-ring-default               act/unsup
          1004 fddinet-default                  act/unsup
          1005 trnet-default                    act/unsup

          VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
          ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
          1    enet  100001     1500  -      -      -        -    -        0      0
          1002 fddi  101002     1500  -      -      -        -    -        0      0
          1003 tr    101003     1500  -      -      -        -    -        0      0
          1004 fdnet 101004     1500  -      -      -        ieee -        0      0
          1005 trnet 101005     1500  -      -      -        ibm  -        0      0

          Primary Secondary Type              Ports 
          ------- --------- ----------------- ------------------------------------------


      Enter the correct mode, either database mode or global configuration mode.

      In order to enter VLAN database mode, issue the vlan database command in privileged mode.

          Switch#vlan database



      Issue the vlan vlan_number command in order to configure a VLAN.

          Switch(vlan)#vlan 2

          VLAN 2 added:
          Name: VLAN0002


          APPLY completed.

      Note: For the configuration to take effect, you can either issue the apply command or exit out of VLAN database mode. The end keyword and Ctrl-Z exit methods do not work in VLAN database mode. Issue the exit command in order to exit out of VLAN database mode.

      Issue these commands in order to perform the VLAN configuration in global configuration mode:

          Switch(config)#vlan 3




      Issue the show run command in order to view VLANs that are numbered higher than 1005 in the running configuration.

          Switch#show running-config

          Building configuration...

          Current configuration : 2975 bytes
          version 12.1
          no service pad
          service timestamps debug uptime
          service timestamps log uptime
          no service password-encryption
          service compress-config
          hostname Switch
          ip subnet-zero
          spanning-tree extend system-id
          mode rpr
          auto-sync standard
          vlan 2000
          interface GigabitEthernet1/1
          interface GigabitEthernet1/2

          !--- Output suppressed.

In Cisco IOS Software, interfaces are in the shutdown state by default, unlike in CatOS-based switches. In CatOS, the port becomes active if it senses the presence of a physical link.

By default, Cisco IOS Software interfaces are Layer 2 interfaces on Catalyst 3550, 3750, and 4500 Series Switches. The interfaces are Layer 3 interfaces on Catalyst 6500/6000 Series Switches. You can configure the interface as a Layer 2 interface with the switchport command in interface configuration mode. You must issue this command before you assign an interface to a VLAN, if the interface is in Layer 3 mode. The command to assign an interface to a VLAN is switchport access vlan vlan_number .

Note: If the interface is configured as a Layer 3 interface, which means that the no switchport command is configured, you cannot assign the interface to a VLAN.

In order to associate the ports to VLANs in Cisco IOS Software, this minimum configuration is required:

    Switch(config)#interface gigabitethernet 3/1


    !--- This command is required if the interface is in Layer 3 mode.

    Switch(config-if)#switchport access vlan 2

    Switch(config-if)#no shutdown

Issue the show interface gigabitethernet module/interface switchport command in order to check the Layer 2 interface status.

    Switch#show interface gigabitethernet 3/1 switchport

    Name: Gi3/1
    Switchport: Enabled
    Administrative Mode: dynamic auto
    Operational Mode: static access
    Administrative Trunking Encapsulation: negotiate
    Operational Trunking Encapsulation: native
    Negotiation of Trunking: On
    Access Mode VLAN: 2 (VLAN0002)
    Trunking Native Mode VLAN: 1 (default)
    Voice VLAN: none
    Administrative private-vlan host-association: none
    Administrative private-vlan mapping: none
    Administrative private-vlan trunk native VLAN: none
    Administrative private-vlan trunk encapsulation: dot1q
    Administrative private-vlan trunk normal VLANs: none
    Administrative private-vlan trunk private VLANs: none
    Operational private-vlan: none
    Trunking VLANs Enabled: ALL
    Pruning VLANs Enabled: 2-1001
    Capture Mode Disabled
    Capture VLANs Allowed: ALL
    Voice VLAN: none (Inactive)
    Appliance trust: none

Assign Multiple Ports to a Single VLAN

You can assign the multiple interfaces on a switch to a single VLAN. Issue these commands:


          Switch(config)#interface range fastethernet [mod/slot - mod/slot]


          Switch(config-if-range)#switchport access vlan vlan_number


          Switch(config-if-range)#switchport mode access


          Switch(config-if-range)#no shut

Note: The interface range command is not supported in all software releases. The interface range command is supported in Cisco IOS Software Release 12.1(13)EW and later.
Remove VLANs

In order to remove a VLAN from the VLAN database, issue the no vlan vlan_number command in either VLAN database mode or global configuration mode. This example uses the VLAN database mode to remove VLAN 2.

    Switch#vlan database

    Switch(vlan)#no vlan 2

    Deleting VLAN 2...


    APPLY completed.

The global configuration mode does not log any message on the console that indicates the deletion of the VLAN. However, you can issue the show vlan command in order to verify the deletion of the VLAN.


Configure Vlan1:

# config t

then specify the interface you want to configure

# interface Vlan1 
# ip address <IP_and_subnet_mask_here>
			# ip address

then to disable the box from auto-shutdown, type the following:

# no shutdown

Exit out of the 'config t' mode by typing 'exit' twice

LabSwitch(config-if)# exit
LabSwitch(config)# exit

then save your configuration by typing the following:

LabSwitch# write mem

you should now be able to log into the box via http://


Understanding the VTP Domain:

 VTP is a Layer 2 messaging protocol that maintains VLAN configuration consistency by managing the addition, deletion, and renaming of VLANs within a VTP domain. A VTP domain (also called a VLAN management domain) is made up of one or more network devices that share the same VTP domain name and that are interconnected with trunks. VTP minimizes misconfigurations and configuration inconsistencies that can result in a number of problems, such as duplicate VLAN names, incorrect VLAN-type specifications, and security violations.

A VTP domain is made up of one or more interconnected network devices that share the same VTP domain name. A network device can be configured to be in only one VTP domain. You make global VLAN configuration changes for the domain using either the command-line interface (CLI) or Simple Network Management Protocol (SNMP).

TransparentóVTP transparent network devices do not participate in VTP. A VTP transparent network device does not advertise its VLAN configuration and does not synchronize its VLAN configuration based on received advertisements. However, in VTP version 2, transparent network devices do forward VTP advertisements that they receive on their trunking LAN interfaces.