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<== Date ==> <== Thread ==>

Subject: Re: CA connection problems between VxWorks and Windows
From: Benjamin Franksen <[email protected]>
To: Michael Davidsaver <[email protected]>, <[email protected]>
Date: Mon, 31 Oct 2016 17:06:23 +0100
On 31.10.2016 16:51, Michael Davidsaver wrote:
> On 10/31/2016 11:33 AM, Benjamin Franksen wrote:
>> On 31.10.2016 15:30, Michael Davidsaver wrote:
>>> On 10/31/2016 07:09 AM, Benjamin Franksen wrote:
>> Anyway, this sort of problem (duplicate IP adresses) should be detected
>> automatically by the network infrastructure IMO, and not left to be
>> debugged by control system engineers after they lead to obscure CA
>> connection failures.
> 
> Oh, I completely agree!  However, I've been bitten by this, so I know
> that detection (or notification of detection) isn't 100%.  I happened to
> notice that the MAC in the arp cache was alternating between two values.

Uargh. That would indeed be hard to detect automatically.

> some relevant links
> 
> https://linux.die.net/man/8/arping
> 
> http://ipwatchd.sf.net

Thanks for the links. A colleague found a tool named arp-scan, which can
be used to implement a simple test:

franksen@tiber > sudo arp-scan -l | grep DUP:
193.149.12.195  00:06:71:33:00:d4       Softing AG (DUP: 2)
193.149.12.196  00:06:71:33:00:d4       Softing AG (DUP: 2)

The tool is packaged in common distros (debian,ubuntu,fedora).

I am currently in the process of trying to get this to run as a test
script for icinga on all our control networks, so perhaps next time we
will be warned earlier...

Cheers
Ben
-- 
"Make it so they have to reboot after every typo." ― Scott Adams

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Re: CA connection problems between VxWorks and Windows Benjamin Franksen
Re: CA connection problems between VxWorks and Windows Michael Davidsaver
Re: CA connection problems between VxWorks and Windows Benjamin Franksen
Re: CA connection problems between VxWorks and Windows Michael Davidsaver

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