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

Subject: Re: Darwin and EPICS_CA_AUTO_ADDR_LIST issue
From: Burkhard Kolb <[email protected]>
To: Jeff Hill <[email protected]>
Cc: [email protected]
Date: Fri, 09 Mar 2007 10:01:49 +0100
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:[email protected]]
Sent: Thursday, March 08, 2007 9:28 AM
To: '[email protected]'
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: [email protected]                |  Tel.: +49 (0)6159 / 71 2667
-------------------------------------------------------------------



--
-------------------------------------------------------------------
Dr. Burkhard Kolb
GSI mbH  |   KP1   |  Planckstr. 1  |  D-64291 Darmstadt
Email: [email protected]                |  Tel.: +49 (0)6159 / 71 2667
-------------------------------------------------------------------

Replies:
RE: Darwin and EPICS_CA_AUTO_ADDR_LIST issue Jeff Hill
References:
Darwin and EPICS_CA_AUTO_ADDR_LIST issue Burkhard Kolb
RE: Darwin and EPICS_CA_AUTO_ADDR_LIST issue Jeff Hill

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