Scanning for services is an easy job for Bob as there are so many tools available from the Internet. In order for him to check the vulnerability of Brownies Inc., he went through a few scanners that are currently available.
Here are the scanners that he used:
Axent’s NetRecon (http://www.axent.com)
SARA, by Advanced Research Organization (http://www-arc.com/sara/)
VLAD the Scanner, by Razor (http://razor.bindview.com/tools/)
However, are there any other alternative ways to make sure that the services that have been scanned will be more accurately reported and detailed for Bob? What would be the best method to accurately identify the services running on a victim host?