Cisco switch IOS basic show commands

command history available:   up/down arrows OR ^P/^N      
edit command line: Home/End OR ^A/^E    left/right arrows OR ^B/^F   Del OR ^D   ^U clears
Can use abbreviations of commands and parameters.  TAB completes
? shows possible next part/step.
Paged output: Enter for next line, Space for next page, q to quit.
Ctrl Shift 6  terminates a command.

enable                      #go into enable/privilege mode

Must be in Enable mode to do these following commands:

show version                #hardware, OS, ports
show flash                  #contents of flash memory
  dir flash:subdirectory

show running-config         #non-default settings
  sh ru

show ip interface brief     #ports up or down  ("up and up")
  sh ip int br

show interfaces status      #summary of ports:which ports are connected, at what duplex and speed
show interfaces [INTERFACE] #info and stats about a port, or all ports

show vlan brief             #which ports are in which Vlans

show mac address-table dynamic       #learned MAC addresses table.   Port->MAC
OLD: show mac-address-table dynamic  #learned MAC addresses table.   Port->MAC
  sh mac addr dy
 clear mac-address-table dynamic     ??[interface INT | address MAC]


show arp                    #arp cache
show users                  #logged-on users   *'ed line is you

#find port your telnet session is connected to:
sh users          find your IP         
sh arp            then your MAC
sh mac addr dy    then your port

ping IP.ADDR      #if vlan1 IP address is set



show port-security interface INTERFACE

show cdp neighbors               #directly connected switches and routers