Re: udpiiu messages

[Torsten Bögershausen via Tech-talk <tech-talk at aps.anl.gov>]

Mark,
which version of EPICS base is running on the IOC ?
(probably a useless question, since BASE 7.010 has the same message)
The short explenation is, that someone is sending rubbish
(in the EPICS ca sense) to an EPICS UDP port.
There is now way to turn that message off, to my knowledge, after
reading the code.

(I think that udpiiu is responsible for repeater business)
It would be nice to try to run a tshark/tcpdump to see what is going on.

HTH
/Torsten




On 2026-01-29 15:26, Mark Rivers via Tech-talk wrote:
> Folks,
>
> I am seeing error messages like this printed in the Linux shell 
> periodically:
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.250:3956 ignored
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.250:3956 ignored
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.246:3956 ignored
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.250:3956 ignored
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.246:3956 ignored
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.250:3956 ignored
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.246:3956 ignored
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.250:3956 ignored
> ../udpiiu.cpp: Undecipherable (payload too small) UDP msg from 
> 10.54.160.246:3956 ignored
> The messages are being printed from udpiiu.cpp in EPICS base.  I believe 
> they are generated by medm that is running in the background.  medm is 
> built with base 7.0.7.
> I believe port 3956 is used for GigEVision.  This suggests that the 
> devices with those IP addresses could be cameras, but they are not 
> registered in our DNS.  I am trying to track them down.
> However, given that the messages appear to have nothing to do with 
> EPICS, why is EPICS base printing an error message, rather than simply 
> ignoring them?
> What do these messages mean, and can they be turned off?
>
> Thanks,
> Mark