Which of the following are true about firewalls?
I. They are an important part of any network security strategy
II. They are the electronic equivalent of a guard at a gate
III. They can be hardware or software
IV. They are used to checks all data passing in or out to make sure it is legit
V. They should allow users access to all the resources they need
VI. They should keep out any malicious users or programs
I - III only
IV-VI only
I-IV and VI
I - Vl all
