TCP wrapper

A TCP wrapper is software to protect against unwanted access from a computer network. There are several implementations of TCP wrappers. Some operating system has a TCP wrapper daemon called tcpd implemented.

On the one hand, a superserver like inetd can query a TCP wrapper before passing on access or not. On the other hand, some servers can themselves query a TCP wrapper before responding to an access or not.

TCP wrappers include the two files /etc/hosts.allowand /etc/hosts.deny, in which the permitted and denied remote stations are entered, for example by DenyHosts . Ultimately, TCP wrappers are a program library created by Wietse Venema which , in order to be used, must be linked and linked accordingly.

Individual evidence

↑ TCP wrapper . In: The FreeBSD Handbook . FreeBSD Foundation .
↑ Configuring TCP Wrappers on MAC OS X . Boston University .
↑ Configuring TCP Wrappers . In: UnixWare 7 Documentation . SCO Group .
^ Daniel J. Barrett, Richard E. Silverman: SSH, The Secure Shell: The Definitive Guide . O'Reilly , 2001, ISBN 0-596-00011-1 , Forwarding Security: TCP-wrappers and libwrap ( online ).

[1] TCP wrapper . In: The FreeBSD Handbook . FreeBSD Foundation .

[2] Configuring TCP Wrappers on MAC OS X . Boston University .

[3] Configuring TCP Wrappers . In: UnixWare 7 Documentation . SCO Group .

[4] Daniel J. Barrett, Richard E. Silverman: SSH, The Secure Shell: The Definitive Guide . O'Reilly , 2001, ISBN 0-596-00011-1 , Forwarding Security: TCP-wrappers and libwrap ( online ).