Show commands are Very Important in Troubleshooting

The most important point in studying is to know how to troubleshoot running protocols and devices

here i’ll put the most common and most used show commands and there use isa

1st

#show running configuration

it’s the most used command because it shows use every command that is running in the device and also shows you if there are wrong commands or wrong configurations

2nd

#show ip interface brief
this command is really great too because it shows is every interface logical or physical in the device and from there you can see the IP Add of every interface and if the interface is up or down

you must check the interface and see if it is up up, means must be up in STATUS & in PROTOCOL also

see this

It shows that the interfaces are down down
the 1st down means that the interface is still shutdown and the admin didn’t use the command #no shutdown

so always use the command no shutdown to open the interface,

the second down means the protocol is not working, means that the interface is not connecting with the other interface on the other device, so you should check the ip address if it’s in the same subnet as the other interface, and check also if the other interface is up up

and check if there is a protocol using this interface, you will need to use the show running configuration command to check the interface and the protocols.

3rd

#show ip route

this command shows you the routing table and from that u can see the routing protocol running and there networks and you can see also the source address from which you got the route

these are 3 show command which i think are the most important and the most basic commands you’ll almost use every time you use a Cisco device

many problems are just wrong commands typed in the device or as simple as that so don’t forget these commands and when using them especially the show running config command make sure you check every command in the list and see if it’s written write and the ip address and the subnet masks also

these will be great help also in the CCNA exam  so becarefull

I hope that helps all of who are taking the CCNA exam and also in real life

P.S:

The #show running configuration command helped me in an interview i did coz the interviewer asked me to gather the info i can about the device so when i used the comman i saw every command they are using and all the protocols also :D, aslo use #show version to check what kind of devices i’m in 😛

~ by Network Techs. on September 2, 2009.