Catalyst 2950 and 3550 Series

Catalyst 2950 and 3550 Series
To configure VLANs on an IOS-based switch, first you need to enter the VLAN database. This
mode is entered by typing the command vlan database. This command changes the prompt, as
can be seen from the next example. Once in this new privileged mode, use vlan vlan# name vlan_
name. Note that you do not enter the standard configuration mode to enter this configuration:
Terry_2950#vlan database
Terry_2950(vlan)#vlan ?
<1-1005> ISL VLAN index
Terry_2950(vlan)#vlan 2 ?
are Maximum number of All Route Explorer hops for this VLAN
backupcrf Backup CRF mode of the VLAN
bridge Bridging characteristics of the VLAN
media Media type of the VLAN
mtu VLAN Maximum Transmission Unit
name Ascii name of the VLAN
parent ID number of the Parent VLAN of FDDI or Token Ring type VLANs
ring Ring number of FDDI or Token Ring type VLANs
said IEEE 802.10 SAID
454 Chapter 14  VLANs, Trunks, and VTP
state Operational state of the VLAN
ste Maximum number of Spanning Tree Explorer hops for this VLAN
stp Spanning tree characteristics of the VLAN
tb-vlan1 ID number of the first translational VLAN for this VLAN (or zero
if none)
tb-vlan2 ID number of the second translational VLAN for this VLAN (or zero
if none)
<cr>
Terry_2950(vlan)#vlan 2 name ?
WORD The ascii name for the VLAN
Terry_2950(vlan)#vlan 2 name marketing
VLAN 2 added:
Name: marketing
Terry_2950(vlan)#vlan 3 name production
VLAN 3 added:
Name: production
Terry_2950(vlan)#exit
APPLY completed.
Exiting....

Remember that a created VLAN is unused until it is mapped to a switch port or
ports, and that all ports are always in VLAN 1 unless set otherwise.
After you create the VLANs that you want, you use the show vlan command to see the configured
VLANs. However, notice that, by default, all ports on the switch are in VLAN 1. To
change that, you need to go to each interface and tell it what VLAN to be a part of:
Terry_2950#show vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4
Fa0/5, Fa0/6, Fa0/7, Fa0/8
Fa0/9, Fa0/10, Fa0/11, Fa0/12
Fa0/13, Fa0/14, Fa0/15, Fa0/16
Fa0/17, Fa0/18, Fa0/19, Fa0/20
Fa0/21, Fa0/22, Fa0/23, Fa0/24
2 marketing active
Scaling the Switch Block 455
3 production active
1002 fddi-default active
1003 token-ring-default active
1004 fddinet-default active
1005 trnet-default active
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
1003 tr 101003 1500 - - - - - 0 0
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1004 fdnet 101004 1500 - - - ieee - 0 0
1005 trnet 101005 1500 - - - ibm - 0 0
Remote SPAN VLANs
------------------------------------------------------------------------------
Primary Secondary Type Ports
------- --------- ----------------- ------------------------------------------

Terry_2950(config-if)#switchport ?
access Set access mode characteristics of the interface
host Set port host
mode Set trunking mode of the interface
nonegotiate Device will not engage in negotiation protocol on this
interface
port-security Security related command
priority Set appliance 802.1p priority
protected Configure an interface to be a protected port
trunk Set trunking characteristics of the interface
voice Voice appliance attributes
456 Chapter 14  VLANs, Trunks, and VTP
Terry_2950(config-if)#switchport access ?
vlan Set VLAN when interface is in access mode
Terry_2950(config-if)#switchport mode access
Terry_2950(config-if)#^Z
Terry_2950#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Terry_2950(config)#int fa 0/2
Terry_2950(config-if)#switchport ?
access Set access mode characteristics of the interface
host Set port host
mode Set trunking mode of the interface
nonegotiate Device will not engage in negotiation protocol on this
interface
port-security Security related command
priority Set appliance 802.1p priority
protected Configure an interface to be a protected port
trunk Set trunking characteristics of the interface
voice Voice appliance attributes
Terry_2950(config-if)#switchport mode ?
access Set trunking mode to ACCESS unconditionally
dynamic Set trunking mode to dynamically negotiate access or trunk mode
trunk Set trunking mode to TRUNK unconditionally
Terry_2950(config-if)#switchport mode access
Terry_2950(config-if)#switchport access ?
vlan Set VLAN when interface is in access mode
Terry_2950(config-if)#switchport access vlan 2
Terry_2950(config-if)#^Z
Now you need to confirm that the configuration has been accepted and the port to VLAN
relationship has been established. You can use the show vlan command we used earlier, but the
VLANs will also be shown in the running configuration:
Terry_2950#show run
00:49:36: %SYS-5-CONFIG_I: Configured from console by consolesho run
Building configuration...


Current configuration : 1512 bytes
version 12.1
[output cut]
interface FastEthernet0/2
switchport access vlan 2
switchport mode access
no ip address
Now, type show vlan to see the ports assigned to each VLAN:
Terry_2950#show vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/1, Fa0/3, Fa0/4, Fa0/5
Fa0/6, Fa0/7, Fa0/8, Fa0/9
Fa0/10, Fa0/11, Fa0/12, Fa0/13
Fa0/14, Fa0/15, Fa0/16, Fa0/17
Fa0/18, Fa0/19, Fa0/20, Fa0/21
Fa0/22, Fa0/23, Fa0/24
2 marketing active Fa0/2
3 production active
1002 fddi-default active
1003 token-ring-default active
1004 fddinet-default active
1005 trnet-default active
[output truncated]
Terry_2950#