FOR WHICH FIREWALLS CAN’T PROVIDE SECURITY

 In addition, Firewalls can’t  provide security for the following.

1 .A firewall can’t protect against attacks that don’t go through the firewall. Many corporations that connect to Internet are very concerned about confidentially date leaking out of company through route. However, a magnetic tape can just export data.

2. Many organizations that are terrified of Internet connections have no coherent policy about how dial-in access via modems should be protected. There are many organizations out there buying expensive firewalls and neglecting the numerous other back doors into their network.

3. Another thing a firewall can’t really protect you against is traitors or idiots inside the network. An industrial spy might leak information or export it through a telephone, FAX or floppy disk. Firewalls can’t protect you against this stupidity.

4. Firewalls can't protect very well against things like viruses. There are too many ways of encoding binary files for transfer over networks, and too many different architectures and viruses to try to search for them all. In other words, a firewall cannot replace security-consciousness on the part of your users. In general, a firewall cannot protect against a data-driven attack--attacks in which something is mailed or copied to an internal host where it is then executed.

Organizations that are deeply concerned about viruses should implement organization-wide virus control measures. Rather than trying to screen viruses out at the firewall, make sure that every vulnerable desktop has virus-scanning software that is run when the machine is rebooted. Blanketing your network with virus scanning software will protect against viruses that come in via floppy disks, modems, and Internet. Trying to block viruses at the firewall will only protect against viruses from the Internet--and the vast majority of viruses are caught via floppy disks.