Which Cisco IOS command can be used to troubleshoot switch startup problems on a Cisco Catalyst 2950
switch?

A.
show test

B.
show diagnostic

C.
show post

D.
show switchstartup

Explanation:
The Cisco IOS command show post is used on the 2900/3500XL, 2950/2955, 3550, 2970, and 3750 series
switches to view and troubleshoot issues related to the Power On Self-Test (POST) on the switch. This
command will find the POST test that failed on startup.
The show test command is incorrect because it is a CatOS command, not a Cisco IOS command. The Cisco
2950 uses a Cisco IOS operating system and not the Catalyst operating system. The show test command is
used on a switch to view any hardware errors that occurred at startup. It also provides information on the errors
returned from the diagnostic tests. The following parameters can be used with this command:
mod: An optional parameter used to specify the module number.
diaglevel: Used to view the diagnostic level.
diagfail-action: Used to view information on the action taken by the supervisor engine after the failure of a
diagnostics test.
The following code is a sample output of this command for module 2:

The show diagnostic command is incorrect because this command is used on the Catalyst 6000 series, not the
2950. A variant of the command, show diagnostics, is used for the Catalyst 4000 series. These commands can
be used on the relevant switches to view any hardware errors that occurred on startup. This command displays
the Power-On Self-Test (POST) results.
The show switchstartup command is not a valid Cisco IOS command.
Objective:
Infrastructure Management
Sub-Objective:
Use Cisco IOS tools to troubleshoot and resolve problems

Cisco>Home>Support>Product Support>End-of-Sale and End-of-Life Products>Cisco Catalyst 6000 Series
Switches>Troubleshoot and Alerts> Troubleshooting TechNotes> Troubleshooting Switch Port and Interface
Problems> Most Common Port and Interface Troubleshooting Commands for CatOS and Cisco IOS
Cisco Documentation > Catalyst 3550 Multilayer Switch Hardware Installation Guide, Dec 2002 >
Understanding POST Results