Re: pvlist does not find all servers in network

["Johnson, Andrew N. via Tech-talk" <tech-talk at aps.anl.gov>]

Hi Florian,

Which version of Base is this IOC running? Are you using pvlist from the same Base version? (Not that it should matter). My local run of your “netstat” command here looks equivalent, do both your client and the crate have the same broadcast IP address?

The output from “uname -a” might be helpful, given the age of your distro.

There is an environment variable EPICS_PVA_DEBUG that you can set (numeric, I suspect larger numbers print more stuff) when running the IOC to get information about what the server is doing.

HTH,

- Andrew

-- 

Complexity comes for free, Simplicity you have to work for.

On 1/27/26, 6:08 AM, "Tech-talk" <tech-talk-bounces at aps.anl.gov> wrote:

Small addendum:

I stopped the IOC on the crate controller and opened a UDP socket in
python listening on port 5076 and afterwards running `pvlist` on the PC
again:

 >>> import socket
 >>> sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
 >>> sock.bind(("", 5076))
 >>> data, addr = sock.recvfrom(1024)
 >>> print( data, addr )
b'\xca\x02\x00\x03\x1d\x00\x00\x00\x00\x00\x00\x00\x81\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\x00\x00\x00\x004\xb4\x00\x00\x00'
('192.168.10.53', 46132)
 >>>

So, the python socket receives the UDP broadcast from the PC.
Therefore I guess there is an issue with the IOC....is there any way of
debugging the PVAserver?

Cheers,
Florian

On 1/27/26 13:02, Florian Feldbauer via Tech-talk wrote:
> Hey all,
>
> I have a strange problem, that I haven't encountered before.
>
> In our lab we have a small test setup for our pixel sensors.
> As HV/LV power supply for these sensors we use a Wiener MPOD crate
> with an iseg Crate Controller.
> The crate controller is running Linux (The Ångström Distribution
> v2017.12) and an EPICS IOC with PVA.
>
> Now, when I run `pvlist` from another PC I see a list of all the IOCs
> running in this network except the one on the iseg Crate Controller.
> When I explicitly run `pvlist iseg-iCS2-5230317` I get a list of all
> PVs from that IOC, so PVA communication works in general, but for some
> reason this IOC is not reacting on broadcasts.
>
> I checked with netstat and for me this looks correct:
>
>> root@iseg-iCS2-5230317:~# netstat -tuln | grep 5076
>> udp        0      0 224.0.0.128:5076        0.0.0.0:*
>> udp        0      0 192.168.10.255:5076     0.0.0.0:*
>> udp        0      0 192.168.10.22:5076      0.0.0.0:*
>> udp        0      0 224.0.0.128:5076        0.0.0.0:*
>> udp        0      0 192.168.10.255:5076     0.0.0.0:*
>> udp        0      0 192.168.10.22:5076      0.0.0.0:*
>> udp        0      0 :::50767                :::*
>
> There is no firewall running on the crate controller.
>
> Any idea what could cause this issue?
>
> Cheers,
> Florian
>
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AG der Experimentalphysik I
Dr. Florian Feldbauer
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