A firewall that may be used in a power integrated network having a plurality of computer systems is powered by the power integrated network. To that end, the firewall includes an input module that receives data addressed to a given computer system in the power integrated network, a security module for determining if the data received at the input module can be forwarded tot he given computer system, and a power module to power both the input module and the security module. The power module receives its power from the power integrated network.