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[Support #HDQ-517625]: Assistance requested for "Gap in packet sequence" log entries from noaaportIngester

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  • Subject: [Support #HDQ-517625]: Assistance requested for "Gap in packet sequence" log entries from noaaportIngester
  • Date: Thu, 02 Jul 2020 09:08:51 -0600
Hi Gregg,

> > The Gap errors have gone away.  SPC identified *another* NOVRA box with
> > just PID 106 configured to multicast on our public network 140.90.173.x
> > The SBN1 and SBN2 servers have direct connections to NOVRA boxes and these
> > servers *also* sit on the 140.90.173.x network.  So the noaaportIngester
> > was receiving data from two different NOVRA boxes (i.e. the direct connect,
> > and the NOVRA multicasting on 224.0.1.6 via the 140.90.173.x network).
> >
> > Question, even though the various instances of noaaportIngestor are running
> > and specifically listening to configured multicast addresses (i.e. see
> > below), can they also pick up a multicast on 224.0.1.6, which isn't
> > configured via ldmd.conf (see below)?
> 
> This is a question for Steve.  But, I have to add that the original setup
> on SBN1 was to explicitly specify the Ethernet interface to listen to for
> the various ports/PIDs.  I do not know how traffic on one Ethernet
> interface could affect that on a different Ethernet interface.

noaaportIngester(1) bind(2)s its input socket to the multicast IP address and 
port number and, if the "-I <interface>" option is used, calls setsockopt(2) to 
join the multicast group on the specified interface. Under these conditions, it 
will only receive packets sent to that multicast IP address and port number 
that are seen by that interface.

Be sure to use the "-I <interface>" option.

If something on the computer was sending to that multicast group address on 
that interface, those packets would also be received by the noaaportIngester(1) 
process.

This assumes that the operating system and hardware all work correctly.

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: HDQ-517625
Department: Support NOAAPORT
Priority: Normal
Status: Closed
===================
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