We need help on analyzing the adverse effect of using
.htaccess to block misbehaving IP addresses.

We first installed the file in September 1999 to block a
single looping machine at kisa.or.kr. Then added a few
more as such loopings occurred from other addresses.

Recently we discovered that nearly all our logfiles have been
inaccurate and asked our provider, Verio, to tell us why. Turns
out the culprit was .htaccess, according to Verio. We were 
blamed for listing hostnames to block rather than numeric
IP addresses, which led reverse lookup to go haywire (see 
message below).

Removal of .htaccess immediately stopped the inaccuracies,
and reinstallation with only numeric addresses seems to
work just fine, so that seems to have been the problem.

We are attempting to analyze the inaccurate logs for a particular
brief period and cannot find a pattern which would produce accuracy.
(Yes, we regularly delete logfiles to protect privacy) Verio claims 
that the inaccurate logs were generated automatically and there is 
no way to regenerate them accurately.

Help would be appreciated on means to figure out how to translate
the inaccuracies into accuracies. This involves only about two dozen
logfile entries we need to accurately identify (more on that when the
details can be substantiated -- it's about gov-snooping).

A related odd discovery: Last December, visitors from ncsc.mil,
including what we call the "NSA bot," disappeared from the logfiles.
We assumed the site was no longer of interest or that cover
addresses were now being used.

Well, maybe wholly coincidental, when we removed .htaccess
a few days ago the ncsc.mil addresses, including the NSA bot, began 
reappearing in the logfiles. Reinstallation of .htaccess with only numeric
addresses has had no affect on the ncsc accesses.

Would anyone know what to make of this?

----------

From:  David Klein <[EMAIL PROTECTED]>
Subject: Re: [IDS-946244] CRYPTOME.ORG and JYA.COM 
To: [EMAIL PROTECTED]
Date: Fri, 12 May 2000 07:41:55 -0400 (EDT)

Dear John,

Thank you for contacting technical support. In response to your questions:

Our Apache implementation has HostnameLookups turned off - the 
access_log.custom file should NOT have hostnames in it. The lookups are 
done by logparse/logip when the servers' master log file is parsed. However, 
you had a bunch of 'deny from' directives in his .htaccess that used 
hostnames:

[addresses xxx'd here for privacy]

<Limit GET>
order allow,deny
deny from 165.xx.xx
deny from xxx.virtualwebsites.com
deny from xxx.att.com
deny from xxx.att.com
deny from xxx.att.com
deny from xxx.nj.dial-access.att.net
deny from 208.xxx.xxx.xxx.flyswat.com
allow from all
</Limit>

This forces Apache to look up the hostnames, so it knows where to 
deny from. Since they are already looked up, they are put into the 
log. So, when logparse runs, it takes the hostname, thinks it's an IP 
address, and tries to reverse it - with unpredictable results. You will 
need to put only IP addresses in your .htaccess file. We tried 
commenting out the entries with hostnames and then only IPs 
were logged - which would be correctly parsed by logip. I hope 
this clarifies things a bit more for you. If you wish to find some more 
information about Apache configurations, please take a look at
http://home.verio.net/support/hosting/htaccess.cfm. There are also 

some links there for more detailed information about Apache 
modifications. If you have any other questions, please feel free to 
contact us. Have a good day.

Sincerely,
David K.
Tech Support





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