Summary: TCPWrap Host addr. always

From: <>
Date: Mon Aug 06 2001 - 05:47:43 EDT
Hello all,

my problem concerning the tcpwrapper program is now solved, special thanks
to Casper Dik and Angel L. Mateo!
Let me first explain the problem by re-sending my old mail:

> Hello,
> I apologize if anyone has already answered this question, because this
> is my first posting to this mailing list.
> I'm trying to increase our network security by installing "tcpwrap" by
> Wietse Venema, which is recommended on many sites, including this
> mailing list. But, unfortanetly, it doesn't work...
> The system I use to test it is a Ultra 10, running Solaris 8 with the
> newest patches installed. I've installed and configured tcpwrap as
> described in the "advanced config" section in the Readme, but without
> writing any hosts.allow/hosts.deny files, since I - as it is recommended
> in the manual - first want to try it.
> The tcpd work, every attempt to connect is logged in /var/log/syslog, as
> I expected, but the hostaddress is always written as "". I've
> tried to install other versions of tcpwrap, even the ipv6-Version
> (although I don't use IP Verison 6 at all), but without success.
> The testmachine is set up correctly, and I can resolve every hostname
> with "nslookup" and other tools, but it's not logged. I've already
> searched the internet for any advises, and even try to dig in the code,
> but without success. So, this is my last try, :-))
> Hope you can help me!

After my posting to the sunmanagers list, I've also send a mail to Wietse
Veenema, who has programmed TCPWrap. And, I got an automatic reply which I
think is useful to post it to this list:


    On SOLARIS 8+ and AIX 4.3+ use the IPV6-enabled version by
    Casper Dik at
    Be sure to specify HAVE_IPV6 in the Makefile (see comments in
    that file for instructions).

    If you run an IP version 6 enabled version of TCP Wrapper and
    still see connections from, you forgot to specify
    HAVE_IPV6 in the Makefile. or you forgot to specify tcp6 in
    the inetd.conf file.

    If tcpd shell commands fail with a "bad option name" error
    message, have a look at the first paragraph of the hosts_options.5

    If tcpd access rules do not work as expected, run "tcpdchk -v"
    and see if its output matches your expectation. If that does
    not clear things up, please use the "tcpdmatch" command, report
    what it says, and also report what result you expected to get.
    Both commands come with the tcp wrapper source code. See
    tcpdchk.8 and tcpdmatch.8 for documentation (`nroff -man'

    Otherwise, if you see connections from, someone may be
    portscanning your machine, by making brief connections that
    end before tcpd has a chance to run. If this happens a lot you
    might want to consider running a sniffer program such as tcpdump.

    If tcpd banners and other features in hosts_options.5 do not
    work, please read the first paragraph of the hosts_options.5
    manual page.

    SOLARIS 7: the try-from command produces garbled output when
    run from, for example, rsh. In order to fix, remove the #ifdef
    TLI code in try-from.c.

    SOLARIS: if you have trouble building TCP Wrapper, please look
    carefully at the error messages.

    SOLARIS: if the build fails with with: "/usr/ucb/cc:  language
    optional software package not installed" you must either spend
    $$ on the SUN C compiler, or you download and install GCC. See
    the SOLARIS FAQ at

    SOLARIS: if you have trouble building TCP Wrapper with GCC
    after upgrading the SOLARIS software, you are probably still
    using the include files from the PREVIOUS SOLARIS release (look
    at the exact error message).  Fix: run the fixincludes command
    that comes with GCC, re-install GCC from scratch, or install
    GCC 2.8.

    HP-UX: if you have trouble building TCP Wrapper, and the
    compilation fails with: /usr/ccs/bin/ld: Unsatisfied symbols:
    yp_get_default_domain (code), edit the Makefile and add
    -DUSE_GETDOMAIN to the definition of the BUGS macro.

    LINUX: if you have trouble building TCP Wrapper version 7.5
    get, the current version

    LINUX: if the compilation fails with: percent_m.c:17: conflicting
    types for `sys_errlist', edit the "linux" entry in the Makefile,
    and add a -DSYS_ERRLIST_DEFINED directive like this:

	    LIBS= RANLIB=ranlib ARFLAGS=rv AUX_OBJ=setenv.o NETGROUP= \

(There were more hints for other programs written by Wietse, like SATAN,
LogDaemon and so on, but I decided not to put them in this mail).
So, the solution is that you have to use the TCPWrap_ipv6 suite and
specially enable IPv6-Support in the Makefile on Solaris 8, even if you
don't use IPv6 addresses...
(Carsten's answer pointed also to this solution)
Simple solution for a big problem, which is not documented in the
Readme-Files delivered with tcpwrap.

Again, thanks to everyone for reading + answering,

best regards,

Harald Husemann
System Administrator
Materna GmbH Informations + Communications
Vokuhle 37
44141 Dortmund, Germany
Received on Mon Aug 6 10:47:43 2001

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