Real World Linux Security Prentice Hall Ptr Open Source Technology Series

8.4 Mainframes Within Your Control

Many mainframes, especially older ones, were not designed to be operated in an insecure environment and should not be. They especially should not be on a corporate network that has many desktop systems on it and may have a bridge to the Internet.

Instead, if access to the mainframes from other systems is needed, "front end" systems should be interfaced directly to the mainframes over private networks. These front end systems should be treated as firewalls protecting their respective mainframes. Linux is a fine choice here.