Troubleshooting Commands


ping


The ping command is used to test connectivity to another device on the network

Usage

The most simple use case is ‘ping [ip address]

ping 192.168.1.1

This command can be used from Linux, Windows and Cisco IOS devices


traceroute


The trace command is used to view all the ‘hops’ a packet makes when being sent to a destination on the network.

Usage

The most simple use case is ‘tracert [ip address]’ for Cisco IOS and Linux devices:

traceroute 192.168.1.1

However, this command is also available Windows devices:

tracert 192.168.1.1

show running-config


Shows the running configuration of a Cisco IOS device. Really important troubleshooting command especially if you know YAML

Usage

To use this command you must be in Privilaged EXEC mode

router# show running-conifg

show interface



show ip interface



show ipv6 interface



show ip route



show ipv6 route



show vlan



show cdp neighbor




show ip ospf database




Switch Verification Commands


show interfaces


Display interface status and configuration. Useful for checking for connectivity issues liek exessive noise on the line

switch# show interfaces [inteface-id]

show flash


Display information about flash file system.

switch# show flash

show version


Display system hardware and software status.

switch# show version

show history


Display history of command entered.

switch# show history

show ip interface


Display IP information about an interface.

switch# show ip interface [interface-id]

show ipv6 interface


Display IPv6 information about an interface.

switch# show ipv6 interface [interface-id]

show mac-address-table


Display the MAC address table.

switch# show mac-address-table