19990820: We are having problems again...

>From: McIDAS <address@hidden>
>Organization: McIDAS proyect
>Keywords: 199908201415.IAA18376 IDD feed requests

Karli,

Robb Kambic will be responding to this email as well.  I just felt that
it was prudent to get some more information out to you as soon as possible.

>As of last Tuesday we have not been getting any Satellite feeds from any
>of our feed servers. I wasn't aware of the problem until yesterday when
>I tried connecting to our secondary server, however the ldmd.log file
>keeps showing the "Aug 19 05:03:40 3Q:breeze aqua[728]:
>FEEDME(aqua.atmos.uah.edu): 7: Access denied by remote server" error
>with our old server and "Aug 20 00:00:14 3Q:breeze pluto[3895]:
>FEEDME(pluto.met.fsu.edu): 7: Access denied by remote server" from the
>backup server you guys recently set up.

This sounds like something changed on your end.  

>To top it all off, today we've
>lost out NLDN feeds as well (latest feed dates 99231) and it too is
>plagued by the same problem: "Aug 20 00:00:46 3Q:breeze striker[3907]:
>FEEDME(striker.atmos.albany.edu): 7: Access denied by remote server"

The fact that all of your feed sites have started to refuse connections
from you tells me that the problem is almost 100% sure to be on your
end.  To test this out, I did a forward and reverse name lookup for
your ingest machine (breeze.upr.clu.edu):

% nslookup breeze.upr.clu.edu
Server:  laraine.unidata.ucar.edu
Address:  128.117.140.62

Name:    BREEZE.UPR.CLU.EDU
Address:  136.145.165.17

% nslookup 136.145.165.17
Server:  laraine.unidata.ucar.edu
Address:  128.117.140.62

Name:    breeze.uprm.edu
Address:  136.145.165.17

You can see from this pair of nlsookups that the machine names on the
forward and reverse lookup are different.  The LDM does the forward and
reverse lookups to verify that a host is valid; its tests will fail
given the different names.

The question back to you is whether or not you have any control over
this situation?

>we'd been havign serious connection problems with our T1, which
>constantly keeps falling off to the backup gateway.

Could this be the cause of the differning names?

>I thought that was
>the problem originally, but even when the connections are good, we still
>don't get anything. All radar images are OK, for the time being.

The fact that your radar images are OK is strange IF there has been disconnects
and reconnects over the same period of time to the WSI LDM.

>Thanks in advance.

One of the first things that we need to get you to do is initiate dialogs
with your upstream sites when you have problems like this.  It is likely
that an email by you to the site administrator at the feed sites could
resolve your problem a lot quicker than you sending email just to support.

Here is the procedure:

1. Find the email addresses of the site administrators at your upstream sites:

   o start a web browser
   o go to the Unidata WWW HomePage:
     http://www.unidata.ucar.edu
   o go to the Internet Data Delivery (IDD) link:
     http://www.unidata.ucar.edu/projects/idd/index.html
   o go to the Current Operational Status link:
     http://www.unidata.ucar.edu/projects/idd/iddgeneral.html#status
   o go to the IDD site contact list link:
     http://www.unidata.ucar.edu/projects/idd/sitelist.html
   o lookup the email addresses of the site administrators at your upstream
     feed sites:

     University of Alabama-Huntsville
     Scott Podgorny
     address@hidden
     205-922-5819
     
     Florida State University
     Chris Vandersip
     (ldm|cvander)@met.fsu.edu
     904-644-(1550|2522)

     State University of New York at Albany (SUNY-Albany)
     David Knight
     address@hidden
     518-442-4204

2. Send the site administrators your email noting when your service stopped
   and the errors you are seeing in your LDM log file.

3. Make sure to CC address@hidden. on your message so that we
   will be aware of your situation.

I am sending this email to the contacts at your upstream sites that appear
to be refusing your LDM's attempt to connect to try and get you going again.

Scott, Chris, and David:

The University of Puerto Rico has recurring problems with network connections
to their site.  It is possible that the name that their name server
"assigns" them changes when their networking reverts to their backup gateway
causing a mismatch that causes your LDMs to refuse connections.  Would it
be possible to generalize the ALLOW lines in your ldmd.conf files to
allow connections by IP address and by both of the names listed in the
nslookup listing below?  This would help them out greatly IF it fixes
their problem.

Thanks in advance, and please keep us informed about what is going on.

Tom Yoksas