A couple of weeks ago, I wrote about Sun's traffic(1M) showing me
unknown traffic on my net. Many of you responded with the suggestion
that I use etherfind(8) to dig into this further. I then posted
samples of etherfind's output, showing the unknown packets.
Dave Williams (exudnw@exurchin1.ericsson.se) forwarded me a list
of vendors and assigned address families to help with the search.
Unfortunately, the hardware addresses in these mystery packets
did not correspond with any vendor on the list. We finally
isolated and identified the devices, and I thought I'd pass
the information on.
The devices are RAD "Remote Ethernet Bridges" (REB's). These
are DOS PC's with hardware and software for bridging remote
ethernets via serial lines (in our case 56kb lines). The
traffic, according to the manufacturer, is routine communications
between the two bridges at either end of the 56kb line.
"Routine" meaning a packet every 100 ms!
For the record, these boxes use hardware address families
00:00:B0 and 01:00:B0
It seems more than a coincidence that there is only a 1-digit
difference in these two.
Does anyone actually police the utilization of these address
prefixes? Obviously, they're being issued to various vendors,
but is there anything that stops a vendor from just picking one
and using it, which appears to be what might have happended here?
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