Cisco Commands Reference

A comprehensive guide to essential Cisco IOS commands for network configuration and troubleshooting.

Basic Configuration

enable
config terminal
hostname [name]
enable secret [password]
line console 0
password [password]
login
line vty 0 4
password [password]
login
service password-encryption

Interface Configuration

interface [type][number]
ip address [ip-address] [subnet-mask]
no shutdown
description [text]
speed [10|100|1000|auto]
duplex [half|full|auto]

Static Routing

ip route [destination_network] [subnet_mask] [next_hop_address|exit_interface]
ip route 0.0.0.0 0.0.0.0 [next_hop_address] # Default route

Dynamic Routing

# EIGRP
router eigrp [as-number]
network [network-address] [wildcard-mask]

# OSPF
router ospf [process-id]
network [network-address] [wildcard-mask] area [area-id]

# BGP
router bgp [as-number]
neighbor [ip-address] remote-as [as-number]
network [network-address] mask [subnet-mask]

VLAN Configuration

vlan [vlan-id]
name [vlan-name]

interface [interface-id]
switchport mode access
switchport access vlan [vlan-id]

interface [interface-id]
switchport mode trunk
switchport trunk allowed vlan [vlan-list]

Security Configuration

# Access Lists
access-list [number] [permit|deny] [protocol] [source] [destination]
ip access-group [number] [in|out]

# Port Security
switchport port-security
switchport port-security maximum [value]
switchport port-security mac-address [mac-address]
switchport port-security violation [shutdown|restrict|protect]