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[NOAAPORT #REE-844235]: viewing products by the multicast address

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  • Subject: [NOAAPORT #REE-844235]: viewing products by the multicast address
  • Date: Tue, 25 Feb 2020 09:32:21 -0700
Hi Rodger,

re:
> Is there a way to see the products that are being sent on a multicast address?
> For example: products that are on the EXP channel 224.0.1.8.

You can use a system utility like 'tcpdump' to see traffic on an interface.
Here is an example:

<as 'root'>
tcpdump -i eth1 -f

This assumes that the output from your Novra S300N is connected to
the 'eth1' Ethernet interface, so you may need to adjust this.  The
'-f' flag says to print ‘foreign’ IPv4 addresses numerically rather
than symbolically.  The output could then be piped to 'grep' to
limit what you see to the multicast address you are interested in:

tcpdump -i eth1 -f | grep 224.0.1.8

Here is a snippet from the output on one of our CentOS Linux 6.x
NOAAPort ingest machines:

[root@leno ~]# tcpdump -i eth1 -f | grep 224.0.1.8
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
16:30:06.379737 IP 10.0.9.51.37645 > 224.0.1.8.seagull-ais: UDP, length 4068
16:30:06.379875 IP 10.0.9.51 > 224.0.1.8: udp
16:30:06.383051 IP 10.0.9.51 > 224.0.1.8: udp
16:30:06.388799 IP 10.0.9.51.37645 > 224.0.1.8.seagull-ais: UDP, length 4032
16:30:06.389610 IP 10.0.9.51 > 224.0.1.8: udp
16:30:06.393286 IP 10.0.9.51 > 224.0.1.8: udp
16:30:06.399186 IP 10.0.9.51.37645 > 224.0.1.8.seagull-ais: UDP, length 4032
16:30:06.399371 IP 10.0.9.51 > 224.0.1.8: udp
16:30:06.403461 IP 10.0.9.51 > 224.0.1.8: udp
 ...

This, of course, doesn't list full products since the products are sent as
pieces that need to be assembled by the NOAAPort ingest package.


Cheers,

Tom
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Ticket Details
===================
Ticket ID: REE-844235
Department: Support NOAAPORT
Priority: Normal
Status: Closed
===================
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