| reload | Reboots the Cisco switch or router |
| hostname name | Sets a host name to the current Cisco network device |
| copy from-location to-location | Copies files from one file location to another |
| copy running-config startup-config | Replaces the startup config with the active config when the Cisco network device initializes |
| copy startup-config running-config | Merges the startup config with the currently active config in RAM |
| write erase | |
| erase startup-config | Deletes the startup config |
| ip address ip-address mask | Assigns the specified IP address and subnet mask |
| shutdown | |
| no shutdown | Shuts the interface down (shutdown) or brings it up (no shutdown) |
| ip default-gateway ip_address | Sets the default gateway on the Cisco device |
| show running-config | Displays the current configuration of the device |
| show startup-config | Displays the saved configuration stored in the device's NVRAM, which will be loaded when the device starts up |
| description string | Assigns the specified description to an interface |
| show running-config interface interface slot/number | Displays the running configuration for the specified interface |
| show ip interface [type number] | Displays the status of a network interface as well as a detailed listing of its IP configurations and related characteristics. |
| ip name-server serverip-1 serverip-2 | Sets the IP address of or more DNS servers that the device can use to resolve hostnames to IP addresses. |
| |
| Troubleshooting Cisco Commands List | |
| ping *{hostname | system-address} [source source-address]* |
| speed *{10 | 100 |
| duplex *{auto | full |
| cdp run | |
| no cdp run | 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 (or detailed) information about each neighbor connected to the device |
| show interfaces | Displays detailed information about interface status, settings and counters |
| show interface status | Displays the interface line status |
| show interfaces switchport | Displays many 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 VLAN Trunk Protocol (VTP) status, including the current mode |
| |
| Routing and VLAN Commands | |
| show ip route | Displays the current state of the IP routing of all known routes that are either statically configured or learned dynamically through a routing protocol |
| ip route *network-number network-mask {ip-address | interface}* |
| router rip | Enables a Routing Information Protocol (RIP) routing process, which places you in router configuration mode |
| network ip-address | Associates a network with a RIP routing process |
| version 2 | Configures the software to receive and send only RIP version 2 packets |
| no auto-summary | Disables automatic summarization |
| default-information originate | Generates a default route into RIP |
| passive-interface interface | Sets the specified interface to passive RIP mode, which means RIP routing updates are accepted by, but not sent out of, the interface |
| show ip rip database | Displays the contents of the RIP routing database |
| ip nat *[inside | outside]* |
| ip nat inside source *{list{access-list-number | access-list-name}} interface type number[overload]* |
| ip nat inside source static local-ip global-ip | Establishes 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 | Configures a specific Ethernet port on a switch to operate in access mode to accommodate an end device such as a computer, server or printer. The port must then be assigned to a single VLAN. |
| vlan vlan-id [name vlan-name] | Configures a specific VLAN name (1 to 32 characters) |
| switchport mode *{ access | trunk }* |
| 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 | Defines the matching criteria to map 802.1Q frames ingress on an interface to the appropriate service instance |
| show spanning-tree | Provides detailed information about the Spanning Tree protocol for all VLANs |
| |
| DHCP Commands | |
| ip address dhcp | Acquires an IP address on an interface via DHCP |
| ip dhcp pool name | Used to configure a DHCP address pool on a DHCP server and enter DHCP pool configuration mode |
| domain-name domain | Specifies the domain name for a DHCP client |
| network network-number [mask] | Configures 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] | Specifies IP addresses that a DHCP server should not assign to DHCP clients |
| ip helper-address address | Enables forwarding of UDP broadcasts, including BOOTP, received on an interface |
| default-router address[address2 ... address8] | Specifies the default routers for a DHCP client |
| |
| Security Commands | |
| password pass-value | Lists the password that is required if the login command (with no other parameters) is configured |
| username name password pass-value | 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 | Defines the password required when using the enable command |
| enable secret pass-value | Sets the password required for any user to enter enable mode |
| service password-encryption | 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 | Creates and stores (in a hidden location in flash memory) the keys that are required by SSH |
| transport input *{telnet | ssh}* |
| access-list *access-list-number {deny | permit} source [source-wildcard] [log]* |
| 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 |
| permit source [source-wildcard] | Allows 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 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> | Configures the software clock to synchronize a peer or to be synchronized by a peer |
| switchport port-security | Enables port security on the interface |
| switchport port-security maximum maximum | Sets the maximum number of secure MAC addresses on the port |
| switchport port-security mac-address *{mac-addr | {sticky [mac-addr]}}* |
| switchport port-security violation *{shutdown | restrict |
| 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 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 | Displays the state of system logging (syslog) and the contents of the standard system logging buffer |
| terminal monitor | Sends a copy of all syslog messages, including debug messages, to the Telnet or SSH user who issues this command |
