If you want to check if there is an md5sum change on the file /bin/netsat, then you use rpm to VERIFY the contents of everything the package that installed /bin/netstat.
A return of nothing from the above command indicates all files installed by that package are unchanged and valid.
---------- Post added at 08:04 PM ---------- Previous post was at 07:52 PM ----------
If any file in the package has changed, there will be a list of 9 items. A "dot" means no change. A "dot" replaced by a letter has these meanings:
S file Size differs
M Mode differs (includes permissions and file type)
5 MD5 sum differs
D Device major/minor number mismatch
L readLink(2) path mismatch
U User ownership differs
G Group ownership differs
T mTime differs
P caPabilities differ
If you get any file flagged with a "5", it will almost certainly also have a "T" and "S" flag as well.