Re: [EXTERNAL] Re: EPICS CA and PVA across subnets

[Jure Varlec via Tech-talk <tech-talk@aps.anl.gov>]

On 9/29/25 18:39, Kasemir, Kay wrote:

>  Even when you add the IOC to EPICS_PVA_ADDR_LIST, PVA doesn't seem to use TCP to do name searches.

Just like the EPICS_CA_ADDR_LIST, the EPICS_PVA_ADDR_LIST is used for UDP searches.

For TCP, set EPICS_PVA_NAME_SERVERS (just like EPICS_CA_NAME_SERVERS), typically like this to disable the UDP searches:

EPICS_PVA_AUTO_ADDR_LIST=NO

EPICS_PVA_ADDR_LIST=""

EPICS_PVA_NAME_SERVERS=IP-of-PVA-server

That is a good point, I haven't used EPICS_CA_NAME_SERVERS for so long that I have forgotten about it. It is very useful when you are debugging an IOC over SSH where you can only forward a TCP port. That works reliably.

However, it does not work with pvget or pvxget. I now found that pvxget has a very nice -d option that prints a fair bit of info. I can see that it connects to the TCP server, but can't resolve the name. Based on what you wrote, this should work, so I guess it's time to open an issue :)

Best,
Jure