Re: Darwin and EPICS_CA_AUTO_ADDR_LIST issue

[Burkhard Kolb <b.kolb@gsi.de>]

Jeff Hill wrote:
> > On my MAC (OSX 10.4.8), EPICS base-3.14.9, medm 3.11:
> >
> > When I set EPICS_CA_AUTO_ADDR_LIST to NO and have the EPICS_CA_ADDR_LIST
> > pointing to the list of IOCs medm does not find all PVs. Sometimes the
> > connections work for a short time then several IOCs are not seen anymore.
> > If I set it to YES, medm finds them always.
> >
> > In the xterm window I get some error messages from really not existing
> > IOCs:
> > CAC: error = "Host is down" sending UDP msg to 140.181.98.50:5064
> > But the lost ones are not reported!
> >
> > I use the same list of IOCs on other linux boxes and have no problem
> there.
>
> What is the response to "ping -s 140.181.98.50"?
ping: invalid packet size: `140.181.98.50'
Did you mean -R or -r?
Anyhow this IOC is in the list but is actually really down - on purpose.
But most of the other ones are VxWorks 68040 cpus all running the same 
kernel, same setup...
What bothers me most, is that sometimes when I start a medm with a 
screen where vxStats infos from the IOCs is displayed, the IOCs show up 
and then drop out - in the case when EPICS_CA_AUTO_ADDR_LIST=NO.
> PS: Behavior is known to vary between IP kernels for such unicast addresses
> if there are two or more daemons (in this case two or more CA UDP servers)
> listening to the same {IP address, port} tuple on the same host. The typical
> behavior difference is that on certain IP kernels only one daemeon listening
> on UDP port 5064 will receive a UDP message with a unicast destination
> address, but in contrast on other IP kernels all daemeons listening on UDP
> port 5064 will receive such messages. In my experience UDP frames with
> broadcast address destinations always go to all registered listeners
> listening on UDP port 5064 - a uniform behavior across IP kernel
> implementations.
>
> PPS: One possible workaround to the above dilemma is to use directed
> broadcast addresses (router forwarded broadcast addresses) in the
> EPICS_CA_ADDR_LIST. This sometimes requires enabling of "broadcast
> forwarding" features in your routers. We might also add support for
> multicasting to future versions of CA.
We run a flat switched network.

> Jeff
>
> > -----Original Message-----
> > From: Burkhard Kolb [mailto:b.kolb@gsi.de]
> > Sent: Thursday, March 08, 2007 9:28 AM
> > To: 'tech-talk@aps.anl.gov'
> > Subject: Darwin and EPICS_CA_AUTO_ADDR_LIST issue
> >
> > On my MAC (OSX 10.4.8), EPICS base-3.14.9, medm 3.11:
> >
> > When I set EPICS_CA_AUTO_ADDR_LIST to NO and have the EPICS_CA_ADDR_LIST
> > pointing to the list of IOCs medm does not find all PVs. Sometimes the
> > connections work for a short time then several IOCs are not seen anymore.
> > If I set it to YES, medm finds them always.
> >
> > In the xterm window I get some error messages from really not existing
> > IOCs:
> > CAC: error = "Host is down" sending UDP msg to 140.181.98.50:5064
> > But the lost ones are not reported!
> >
> > I use the same list of IOCs on other linux boxes and have no problem
> there.
> > Any idea?
> > --
> > -------------------------------------------------------------------
> > Dr. Burkhard Kolb
> > GSI mbH  |   KP1   |  Planckstr. 1  |  D-64291 Darmstadt
> > Email: B.Kolb@gsi.de                |  Tel.: +49 (0)6159 / 71 2667
> > -------------------------------------------------------------------


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Dr. Burkhard Kolb
GSI mbH  |   KP1   |  Planckstr. 1  |  D-64291 Darmstadt
Email: B.Kolb@gsi.de                |  Tel.: +49 (0)6159 / 71 2667
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