How does TCP Wrappers differ from a firewall?
TCP Wrappers works at the application layer, so it can make access decisions on encrypted data.
TCP Wrappers works at the network layer, so it blocks traffic before the firewall even sees it.
Firewalls are only service specific, whereas TCP Wrappers can block all traffic.
Firewalls easily spawn commands to operate on connection data, whereas TCP Wrappers cannot.