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<H3 align="left"><img src="../../gx/dennis/qbubble.gif"
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>DNS and telnet</H3>
<p><strong>From crabe
</strong></p>
<p align="right"><strong>Answered By Mike Orr
<br></strong></p>
<!-- sig -->
<P><STRONG>
Hi,
How do you get telnet working on your own machine as referred to in the
DNS HOWTO, i.e telnetting at 127.0.0.1 ? I got telnet working to reach
my ISP but never got around telnetting 127.0.0.1. So I gave up DNS.
I have looked around all the HOWTOs available, and perhaps it's too
simple for mentionning.
I am running LinuxPPC2000.
Thanks for any answer.
</STRONG></P>
<BLOCKQUOTE><IMG SRC="../../gx/dennis/bbub.gif" ALT="(!)"
HEIGHT="28" WIDTH="50" BORDER="0"
> [Mike]
Are you trying to do a standard telnet ("telnet 127.0.0.1") or telnet
to another port ("telnet 127.0.0.1 53" would be a DNS query)? Here are
a few possibilities:
</BLOCKQUOTE>
<BLOCKQUOTE><ol>
<li> Nobody is listening on the telnet port. If so, you'll get an immediate
"connection refused" error. Telnetd is normally started from inetd.
Uncomment the telnet line in <TT>/etc/inetd.conf</TT> and "killall -HUP inetd".
<li> Your loopback devide is not configured. What happens when you run
"ping 127.0.0.1"? If you get no response, do "ifconfig". There should
be a stanza for device "lo". If not, run "ifconfig lo 127.0.0.1" and/or
"ifconfig 127.0.0.1 up". (If you're still running kernel 2.0.x, follow that
with "route add -net 127.0.0.0"). Then look at your network startup scripts to
see why it isn't being activated by default.
<li> Inetd runs telnet through a tcpd wrapper for security, and you're failing
the tcpd check. This would cause the connection to do nothing (at least
nothing visible) and then disconnect after a couple seconds. See
"man tcpd" and "man 5 hosts_access".
<li> You are telnetting to port 53 and your nameserver is not running.
If so, you'd get a "connection refused" error. If you installed named
(bind), find out why it isn't running.
</ol></BLOCKQUOTE>
<BLOCKQUOTE>
The TAG security hawks will send a follow-up if I don't also mention
that telnet is a security risk bla bla bla because it doesn't encrypt
your password or your data. Think twice before running telnetd, and
think a third time before allowing tcpd to allow telnet connections from
outside your local network.
</BLOCKQUOTE>
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