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20020815: Trouble Accessing FTP Site via Web (cont.)

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  • Subject: 20020815: Trouble Accessing FTP Site via Web (cont.)
  • Date: Thu, 15 Aug 2002 10:29:12 -0600
>From: Unidata Support <address@hidden>
>Organization: Unidata Program Center/UCAR
>Keywords: 200208141327.g7EDR9K06634 McIDAS-X v2002

Hi Martha,

We reviewed our FTP and TCPD log files and saw numerous refusals for
connection by your machine, wx1sleet.west.tasc.edu/147.81.139.58.  The
problem is that forward lookup for this machine fails:

% nslookup wx1sleet.west.tasc.com
Server:  laraine.unidata.ucar.edu
Address:  128.117.140.62

*** laraine.unidata.ucar.edu can't find wx1sleet.west.tasc.com: Non-existent 
host/domain

even though reverse name lookup succeeds:

% nslookup 147.81.139.58
Server:  laraine.unidata.ucar.edu
Address:  128.117.140.62

Name:    wx1sleet.west.tasc.com
Address:  147.81.139.58

Since we enforce both forward and reverse name lookup before allowing
any FTP connection, your machine was refused.

We also contacted the name servers in your domain and see that they
will not do both forward and reverse name lookup for wx1sleet.  It is
possible that there has been some changes in your network setup
recently to fight known DNS security holes.  If I were you, I would
check with your network folks to find out exactly what is going on.

Tom