How do you verify the trunk configuration on a 3512 (IOS 12.0)? The "sh int trunk" command is not available.
What IOS version exactly? 12.0 is not a complete information. Look at the suffix. If you have a suffix of, say, "XU" (Interim Software release) then this command is not supported. The "show interface status" was only released during the "WC" version of the IOS.