Re: 19990820: We are having problems again...

Unidata Support wrote:
> 
> >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.
> 
Thank you for your promptness!

> >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?

Ok, from what I'd been told by Dr. Winter after I got here, our system
had a similar problem with the domains.  Unfortunately I have absolutely
no control whatsoever over the naming systems here.  The new domain was
changed only recently and they've kept both domains active.  I do know
someone who might have some clout with the main systems.  If you tell me
what would need to be done with the Reverse DNS I ask him if it can be
changed (if that's the problem).  I gave you breeze.uprm.edu as our
server name because that's what the reverse DNS gives us here.


> 
> >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 doubt that these problems would serve as a direct cause, but I can't
count them out.

> >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.
> 
The disconnects are campus wide, so we lose all outside communication
during that period of time.  Maybe the fact that these images are
updated every six minutes might serve as a factor to explain this
anomaly.  However, these feeds have *always* stayed up whenever we've
encountered this type of problem during the past couple of months. 

> >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.
> 
Great, I have noted these instructions and will act accordingly the next
time we have problems.


> 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
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-- 

====================================================================
Amos Winter                                  address@hidden
Director
Puerto Rico Climatology Center 
P.O. Box 9013                           
Department of Marine Sciences                  phone: (787) 265-5416    
University of Puerto Rico - Mayaguez             fax: (787) 265-2195
Mayaguez, PR 00681-9013