This is a cheat sheet for basic Cisco IOS Switch Commands
Command Modes
| Mode | Sample Prompt | What is Allowed |
|---|---|---|
| User EXEC | Switch1> | View Settings |
| Privilege EXEC | Switch1# | View and change settings |
| Global Configuration | Switch1(config)# | Change settings for the whole router (global) |
| Other/Sub Configuration | Switch1(config-if)# Switch1(config-line)# Switch1(config-subif)# .... | Change settings specific to interfaces, terminal lines, sub-interfaces, etc., |
Navigating from User EXEC to Privilege EXEC
Switch1> enable Switch1#
(If password has been set you will be asked for it when you type enable)
Navigating from Privilege EXEC to Global Configuration Mode
Switch1# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Switch1(config)#
Setting Password for Privilege EXEC (Enable Password)
Switch1(config)# enable password abcd1234
(Password is visible in cleartext when running configuration is displayed)
Setting Password with Encryption
Switch1(config)# enable secret abcd1234
(Password is encrypted and is not human readable when running configuration is displayed)
Changing hostname
Switch1(config)# hostname OTGSwitch
Save configuration changes
OTGSwitch# copy running-config startup-config
View running configuration
OTGSwitch# show running-config
Setting an alias
OTGSwitch(config)# alias exec c configure terminal This sets an alias for the command 'configure terminal' as simply 'c'
Getting help
OTGSwitch# ?
This gives general help
OTGSwitch# show ?
This gives the options available for show command.
Configuring the Switch Management Interface
OTGSwitch# configure terminal Enter configuration commands, one per line. End with CNTL/Z OTGSwitch(config)# interface vlan1 OTGSwitch(config-if)# ip address 172.100.1.1 255.255.255.0
This sets IP Address of management interface vlan1
Configure an interface
OTGSwitch(config)# interface FastEthernet0/1 OTGSwitch(config-if)# speed 100 OTGSwitch(config-if)# duplex full
This sets the speed and duplex of interface FastEthernet0/1
Configuring a VLAN
OTGSwitch(config)# interface vlan 2 OTGSwitch(config-if)# description OTGLab VLAN OTGSwitch(config-if)# exit OTGSwitch(config)# interface range FastEthernet 0/1 , FastEthernet 0/5 OTGSwitch(config-if-range)# switchport mode access OTGSwitch(config-if-range)# switchport access vlan 2
This creates a new vlan vlan2, configures FastEthernet interfaces 1 to 5 as access ports and assigns them to vlan2.
Configuring an access port
OTGSwitch(config)# interface FastEthernet 0/10 OTGSwitch(config-if)# switchport mode access OTGSwitch(config-if)# switchport access vlan10
This configures FastEthernet 0/10 as access port and assigns it to vlan10
Configuring a trunk port
OTGSwitch(config)#interface FastEthernet 0/11 OTGSwitch(config-if-range)#switchport mode trunk
This configures Fastethernet 0/11 as a trunk port (can carry traffic for all the VLANs and usually connects switch to another switch)
Configuring etherchannel
of access ports:
OTGSwitch(config)# interface range FastEthernet0/12 -14 OTGSwitch(config-if-range)# switchport mode access OTGSwitch(config-if-range)# switchport access vlan 10 OTGSwitch(config-if-range)# channel-group 5 mode desirable
This configures FastEthernet 12-14 as access ports in vlan10 and makes them an etherchannel group 5 and PAgP negotiation desirable. You have to do similar aggregation of the ports at the device at the other end.
of trunk ports:
OTGSwitch(config)# interface port-channel 4 OTGSwitch(config-if)# switchport trunk encapsulation dot1q OTGSwitch(config-if)switchport mode trunk OTGSwitch(config)# interface range gigabitethernet0/1-2 OTGSwitch(config-if)# switchport trunk encapsulation dot1q OTGSwitch(config-if)# switchport mode trunk OTGSwitch(config-if)# channel-group 4 mode on
This configures GigabitEthernet 1-2 as trunk ports and makes them etherchannel group 4 and mode as on. Same configuration has to be mirrored on other end.
Enable or disable Spanning Tree Protocol (STP)
OTGSwitch(config)# spanning-tree vlan 2 OTGSwitch(config)# no spanning-tree vlan 2
Enables or disables spanning tree for vlan 2 (default is enabled)
Configure STP mode
OTGSwitch(config)# spanning-tree mode rapid-pvst
This sets spanning tree mode as Rapid PVST.
View STP configuration
OTGSwitch# show spanning-tree Enable portfast on a port OTGSwitch(config)# interface FastEthernet 0/1 OTGSwitch(config-if)# spanning-tree portfast
This makes the interface come up fast bypassing STP states and can only be used for regular switch port not for trunk, etherchannel etc.
