tcpdchk - tcp wrapper configuration checker
tcpdchk [-a] [-d] [-i inet_conf] [-v]
tcpdchk examines your tcp wrapper configuration and reports all potential and real prob-
lems 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
Specify this option when tcpdchk is unable to find your inetd.conf network configu-
ration 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 eas-
ier for you to spot any discrepancies between what you want and what the program
The default locations of the tcpd access control tables are:
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 (email@example.com),
Department of Mathematics and Computing Science,
Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands