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

Subject: RE: Channel Access problem over SSH
From: "Hill, Jeffrey O" <johill@lanl.gov>
To: Andrew Johnson <anj@aps.anl.gov>
Cc: "tech-talk@aps.anl.gov" <tech-talk@aps.anl.gov>
Date: Tue, 17 Apr 2012 17:33:20 +0000
> > BTW, in the new server I have allocated a dedicated UDP socket for
> > each of the network interfaces that are discovered on the local host,
> > and during initialization the list of beacon destination addresses is
> > traversed with each of them being assigned to one of these dedicated
> > UDP sockets. This avoids any need to connect a UDP socket to a
> > destination at any time except, using as I recall a temporary UDP
> > socket to determine a local interface used for the beacon's destination,
> > during initialization.
> 
> Sounds like a better setup, although if you still report errors that
> wouldn't help on subnets that have a (possibly incorrectly configured) 
> machine which is sending ICMP responses to broadcast packets.
> 

Since in the new server these, local interface dedicated, UDP sockets are 
bound to a local network interface (with the bind function), but not to 
a destination address (with the connect function), then we will no-longer 
see these oddly mapped (IP ICMP to posix errno) beacon warning messages. 

The EPICS Administrator is nevertheless encouraged to occasionally use 
wireshark, or some similar program, to monitor the ICMP error responses.

Jeff




References:
Channel Access problem over SSH Pavel Masloff
Re: Channel Access problem over SSH Andrew Johnson
RE: Channel Access problem over SSH Hill, Jeffrey O
Re: Channel Access problem over SSH Andrew Johnson

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