tcpdchk - tcp wrapper configuration checker

tcpdchk [-a] [-d] [-i inet_conf] [-v]

tcpdchk examines your tcp wrapper configuration and reports all potential and real problems it can find. The program examines the tcpd access control files (by default, these are /etc/hosts.allow and /etc/hosts.deny), and compares the entries in these files against entries in the inetd network configuration file.

tcpdchk reports problems such as non-existent pathnames; services that appear in tcpd access control rules, but are not controlled by tcpd; services that should not be wrapped; non-existent host names or non-internet address forms; occurrences of host aliases instead of official host names; hosts with a name/address conflict; inappropriate use of wildcard patterns; inappropriate use of NIS netgroups or references to non-existent NIS netgroups; references to non-existent options; invalid arguments to options; and so on.

Where possible, tcpdchk provides a helpful suggestion to fix the problem.

-a

Report access control rules that permit access without an explicit ALLOW keyword.

-d

Examine hosts.allow and hosts.deny files in the current directory instead of the default ones.

-i inet_conf

Specify this option when tcpdchk is unable to find your inetd.conf network configuration file, or when you suspect that the program uses the wrong one.

-v

Display the contents of each access control rule. Daemon lists, client lists, shell commands and options are shown in a pretty-printed format; this makes it easier for you to spot any discrepancies between what you want and what the program understands.

The default locations of the tcpd access control tables are:

/etc/hosts.allow

/etc/hosts.deny

tcpdmatch(8), explain what tcpd would do in specific cases.
hosts_access(5), format of the tcpd access control tables.
hosts_options(5), format of the language extensions.
inetd.conf(5), format of the inetd control file.

Wietse Venema (wietse@wzv.win.tue.nl),
Department of Mathematics and Computing Science,
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513, 
5600 MB Eindhoven, The Netherlands