Cisco Commands

Basic Configuration Commands
Command	Purpose
enable	Logs you into enable mode, which is also known as user exec mode or privileged mode
configure terminal	Logs you into configuration mode
interface fastethernet/number	Enters interface configuration mode for the specified fast ethernet interface
reload	An exec mode command that reboots a Cisco switch or router
hostname name	Sets a host name to the current Cisco network device
copy from-location to-location	An enable mode command that copies files from one file location to another
copy running-config startup-config	An enable mode command that saves the active config, replacing the startup config when a Cisco network device initializes
copy startup-config running-config	An enable mode command that merges the startup config with the currently active config in RAM
write erase erase startup-config	An enable mode command that deletes the startup config
ip address ip-address mask	Assigns an IP address and a subnet mask
shutdown no shutdown	Used in interface configuration mode. “Shutdown” shuts down the interface, while “no shutdown” brings up the interface.
ip default-gateway ip_address	Sets the default gateway on a Cisco device
show running-config	An enable mode command that displays the current configuration
description name-string	A config interface command to describe or name an interface
show running-config interface interface slot/number	An enable mode command to display the running configuration for a specific interface
show ip interface [type number]	Displays the usability status of interfaces that are configured for IP
ip name-server serverip-1 serverip-2	A configure mode command that sets the IP addresses of DNS servers
Troubleshooting Commands
ping {hostname | system-address} [source source-address]	Used in enable mode to diagnose basic network connectivity
speed {10 | 100 | 1000 | auto}	An interface mode command that manually sets the speed to the specified value or negotiates it automatically
duplex {auto | full | half}	An interface mode command that manually sets duplex to half, full or auto
cdp run no cdp run	A configuration mode command that enables or disables Cisco Discovery Protocol (CDP) for the device
show mac address-table	Displays the MAC address table
show cdp	Shows whether CDP is enabled globally
show cdp neighbors[detail]	Lists summary information about each neighbor connected to this device; the “detail” option lists detailed information about each neighbor
show interfaces	Displays detailed information about interface status, settings and counters
show interface status	Displays the interface line status
show interfaces switchport	Displays a large variety of configuration settings and current operational status, including VLAN trunking details.
show interfaces trunk	Lists information about the currently operational trunks and the VLANs supported by those trunks
show vlan show vlan brief	Lists each VLAN and all interfaces assigned to that VLAN but does not include trunks
show vtp status	Lists the current VTP status, including the current mode
Routing and VLAN Commands
ip routenetwork-number network-mask {ip-address | interface}	Sets a static route in the IP routing table
router rip	Enables a Routing Information Protocol (RIP) routing process, which places you in router configuration mode
network ip-address	In router configuration mode, associates a network with a RIP routing process
version 2	In router configuration mode, configures the software to receive and send only RIP version 2 packets
no auto-summary	In router configuration mode, disables automatic summarization
default-information originate	In router configuration mode, generates a default route into RIP
passive-interface interface	In router configuration mode, sets only that interface to passive RIP mode. In passive RIP mode, RIP routing updates are accepted by, but not sent out of, the specified interface.
show ip rip database	Displays the contents of the RIP routing database
ip nat [inside | outside]	An interface configuration mode command to designate that traffic originating from or destined for the interface is subject to NAT
ip nat inside source {list{access-list-number | access-list-name}} interface type number[overload]	A configuration mode command to establish dynamic source translation. Use of the “list” keyword enables you to use an ACL to identify the traffic that will be subject to NAT. The “overload” option enables the router to use one global address for many local addresses.
ip nat inside source static local-ip global-ip	A configuration mode command to establish a static translation between an inside local address and an inside global address
vlan	Creates a VLAN and enters VLAN configuration mode for further definitions
switchport access vlan	Sets the VLAN that the interface belongs to.
switchport trunk encapsulation dot1q	Specifies 802.1Q encapsulation on the trunk link.
switchport access	Assigns this port to a VLAN
vlan vlan-id [name vlan-name]	Configures a specific VLAN name (1 to 32 characters)
switchport mode { access | trunk }	Configures the VLAN membership mode of a port. The access port is set to access unconditionally and operates as a non-trunking, single VLAN interface that sends and receives non-encapsulated (non-tagged) frames. An access port can be assigned to only one VLAN. The trunk port sends and receives encapsulated (tagged) frames that identify the VLAN of origination. A trunk is a point-to-point link between two switches or between a switch and a router.
switchport trunk {encapsulation { dot1q }	Sets the trunk characteristics when the interface is in trunking mode. In this mode, the switch supports simultaneous tagged and untagged traffic on a port.
encapsulation dot1q vlan-id	A configuration mode command that defines the matching criteria to map 802.1Q frames ingress on an interface to the appropriate service instance
DHCP Commands
ip address dhcp	A configuration mode command to acquire an IP address on an interface via DHCP
ip dhcp pool name	A configuration mode command to configure a DHCP address pool on a DHCP server and enter DHCP pool configuration mode
domain-name domain	Used in DHCP pool configuration mode to specify the domain name for a DHCP client
network network-number [mask]	Used in DHCP pool configuration mode to configure the network number and mask for a DHCP address pool primary or secondary subnet on a Cisco IOS DHCP server
ip dhcp excluded-address ip-address [last-ip-address]	A configuration mode command to specify IP addresses that a DHCP server should not assign to DHCP clients
ip helper-address address	An interface configuration mode command to enable forwarding of UDP broadcasts, including BOOTP, received on an interface
default-router address[address2 ... address8]	Used in DHCP pool configuration mode to specify the default router list for a DHCP client
Security Commands
passwordpass-value	Lists the password that is required if the login command (with no other parameters) is configured
username name password pass-value	A global command that defines one of possibly multiple user names and associated passwords used for user authentication. It is used when the login local line configuration command has been used.
enable password pass-value	A configuration mode command that defines the password required when using the enable command
enable secretpass-value	A configuration mode command that sets this Cisco device password that is required for any user to enter enable mode
service password-encryption	A configuration mode command that directs the Cisco IOS software to encrypt the passwords, CHAP secrets, and similar data saved in its configuration file
ip domain-name name	Configures a DNS domain name
crypto key generate rsa	A configuration mode command that creates and stores (in a hidden location in flash memory) the keys that are required by SSH
transport input {telnet | ssh}	Used in vty line configuration mode, defines whether Telnet or SSH access is allowed into this switch. Both values can be specified in a single command to allow both Telnet and SSH access (default settings).
access-list access-list-number {deny | permit} source [source-wildcard] [log]	A configuration mode command that defines a standard IP access list
access-class	Restricts incoming and outgoing connections between a particular vty (into a basic Cisco device) and the addresses in an access list
ip access-list {standard | extended} {access-list-name | access-list-number}	A configuration mode command that defines an IP access list by name or number
permit source [source-wildcard]	Used in ACL configuration mode to set conditions to allow a packet to pass a named IP ACL. To remove a permit condition from an ACL, use the “no” form of this command.
deny source [source-wildcard]	Used in ACL configuration mode to set conditions in a named IP ACL that will deny packets. To remove a deny condition from an ACL, use the “no” form of this command.
ntp peer <ip-address>	Used in global configuration mode to configure the software clock to synchronize a peer or to be synchronized by a peer
switchport port-security	Used in interface configuration mode to enable port security on the interface
switchport port-security maximum maximum	Used in interface configuration mode to set the maximum number of secure MAC addresses on the port
switchport port-security mac-address {mac-addr | {sticky [mac-addr]}}	Used in interface configuration mode to add a MAC address to the list of secure MAC addresses. The “sticky” option configures the MAC addresses as sticky on the interface.
switchport port-security violation {shutdown | restrict | protect}	Used in interface configuration mode to set the action to be taken when a security violation is detected
show port security [interface interface-id]	Displays information about security options configured on the interface
Monitoring and Logging Commands
logging ip address	Configures the IP address of the host that will receive the system logging (syslog) messages
logging trap level	Used in configuration mode to limit messages that are logged to the syslog servers based on severity. Specify the number or name of the desired severity level at which messages should be logged.
show logging	Enable mode command that displays the state of system logging (syslog) and the contents of the standard system logging buffer.
terminal monitor	An enable mode command that tells Cisco IOS to send a copy of all syslog messages, including debug messages, to the Telnet or SSH user who issues this command

NETWORKS FULL FORMS

TCP/IP – Transmission Control Protocol /
 Internet Protocol
LAN – Local Area Network
MAN – Metropolitan Area Network
WAN – Wide Area Network
Modem – Modulation(tor)/Demodulation(tor)
URL – Uniform Resource Location
FTP – File Transfer Protocol
HTTP – Hyper Text Transfer Protocol
PPP – Point to Point Protocol
GSM – Global System for Mobile
CDMA – Code Division Multiple Access
WLL(WiLL)–Wireless in Local Loop
SMS – Short Message Service
WWW – World Wide Web
HTML – Hyper Text Markup Language
XML – eXtensible Markup Language
NFS – Network File System
ARPANET – Advanced Research
 Projects Agency
NSFnet – National Science Foundation
NIU – Network Interface Unit
NIC - Network Interface Card
TAP – Terminal Access Point
 (NIU = NIC = TAP)
VGM – Voice Grade Medium
DGM – Data Grade Medium
STP – Shielded Twisted Pair
UTP – Unshielded Twisted Pair
LED – Light Emitting Diode
LD – Laser Diode
Kbps – Kilo bits Per Second
KBps – Kilo Bytes Per Second
Mbps - Mega Bits Per Second
MBps – Mega Bytes Per Second
Gbps - Giga Bits Per Second
GBps – Giga Bytes Per Second
OFC – Optic Fiber Cable
 Fiber Optic Cable
KHz – Kilo Hertz
MHz – Mega Hertz
GHz – Giga Hertz
THz – Tera Hertz
Bps – Bytes Per Second
bps - Bits Per Second
PDA – Personal Digital Assistants
P-P - Point to Point
AM – Amplitude Modulation
FM - Frequency Modulation
PM – Phase Modulation
A/F – Audio Frequency
(Txd – Transmit Rxd – Receive
RTS – Request to Send
CD – Carrier Detect
DSR – Data Set Ready
CTS – Clear to Send
DTR – Data Terminal Ready)
RJ45 – Registered Jack – 45
BNC – Bayone – Neill – Concelman
AUI – Attachment Unit Interface
SNA – Systems Network Architecture
VFIR – Very Fast Infrared
URI – Uniform Resource Identifier
URN – Uniform Resource Name
MIME – Mail and Multipurpose Internet
 Mail Extensions
POP – Post Office Protocol
SMTP – Simple Mail Transfer Protocol
NNTP – Network News Transfer Protocol
HTTP – Hyper Text Transfer Protocol
NTP – Network Time Protocol
IMAP – Internet Mail Transfer Protocol
SLIP – Serial Line Internet Protocol
IPCP – IP Control Protocol
NCP – Network Control Protocol
LCP – Link Control Protocol
PC – Personal Computer
ISP – Internet Service Provider
SIM – Subscriber Identity Module
TDMA – Time Division Multiple Access
TDM – Time Division Multiplexing
IDEN – Integrated Digital Enhanced
 Network
WCDMA –Wideband CDMA
PSTN – Public Switched Telephone
 Network
3G – Third Generation
UMTS – Universal Mobile
 Telecommunications System /
 Universal Mobile Telephone
 System
EDGE – Enhanced Data rates for Global Evolution
SMSC – Short Message Service Center
HLR – Home Location Register
Email – Electronic Mail
Fax – Fascimile
VSNL – Videsh Sanchar Nigam Limited
DNS – Domain Name Server
DHTML– Dynamic Hyper Text Markup Language
DECnet– Digital’s family of communication protocols
IE – Internet Explorer