General Commands

Elevate privileges

>enable

Enter configuration shell to make changes

>configure terminal

Save Config

>copy running-config startup-config

Save Config (deprecated but works)

>write

Enable cdp globally

>cdp run

Disable cdp globally

>no cdp run

VLANS

Shows the UNTAGGED vlans available on every port.

>show vlan

Inspect each VLAN to see TAGGED vlans available on each port

>show vlan id <int>

Make a vlan

(config)#vlan 3
(config-vlan)#name my-awesome-vlan
(config-vlan)#no shutdown

Setup port`s TAGGED VLANs (Trunk)

(config)#interface Gi0/48
(config-if)#switchport trunk encapsulation dot1q
(config-if)#switchport mode trunk
(config-if)#switchport trunk allowed vlan add 4
(config-if)#switchport trunk allowed vlan remove 1-3
(config-if)#switchport trunk native vlan 5

Set port`s UNTAGGED VLAN

(config)#interface Gi0/1
(config-if)#switchport mode access
(config-if)#switchport access vlan 5

Configure multiple ports at once

(config)#interface range Gi0/1-24
(config-if)#<do whatever>

Delete VLAN

(config)#no vlan <vlan id>

Disable trunk on port

(config-if)#no switchport trunk encapsulation dot1q

Disable CDP on port/interface

(config-if)#no cdp enable

Disable dtp negotiation on port

(config-if)#switchport nonegotiate

Layer 3

Show routing table.

show ip route

Set IP addresses on a VLAN (assigned to a set of ports)

(config)#interface Vlan5
(config-if)#ip address 10.12.34.1 255.255.255.0
(config-if)#no shutdown

Set default route (layer 3) [net/mask/gw]

(config)#ip route 0.0.0.0 0.0.0.0 10.0.1.1

Resetting a switch

Hold the "MODE" button on the front of the switch whilst plugging in the power cable.
SYS LED will start flashing.
Open a serial terminal on 9600 or 115200 depending on model.
switch: flash_init

Initializing Flash...

flashfs[0]: 251 files, 3 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 15998976
flashfs[0]: Bytes used: 15995392
flashfs[0]: Bytes available: 3584
flashfs[0]: flashfs fsck took 10 seconds.
...done Initializing Flash.
switch: dir flash:

Directory of flash:/
    3  -rwx  15411751  <date>               c3750-ipbasek9-mz.122-58.SE2.bin
    5  drwx  7744      <date>               crashinfo_ext
    8  drwx  7744      <date>               crashinfo
  122  -rwx  1915      <date>               private-config.text
  251  -rwx  156       <date>               express_setup.debug
  252  -rwx  2649      <date>               config.text
  253  -rwx  3096      <date>               multiple-fs
  254  -rwx  676       <date>               vlan.dat

3584 bytes available (15995392 bytes used)
switch: rename flash:config.text flash:config.text.disabled
switch: boot
The switch will boot up. At some point it will ask:

Would you like to enter the initial configuration dialog? [yes/no]: 
yes
And from here you can configure the switch as normal.

Accessing the flash

>List files
>dir
>Move

>rename flash:myfile.txt  flash:myfile2.txt
>Copy

>copy flash:myfile.txt  flash:myfile2.txt

Delete file

>delete flash:myfile.txt

Delete directory

>rm  flash:myfiles/