Updated: 2022/Sep/29

Please read Privacy Policy. It's for your privacy.

TCPDCHK(8)                  System Manager's Manual                 TCPDCHK(8)

       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 or tlid network configuration files.

       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

       -a     Report access control rules that permit access without an
              explicit ALLOW keyword. This applies only when the extended
              access control language is enabled (build with

       -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 or tlid.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

       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 (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