Re: Question PVA environment variable

[Michael Davidsaver via Core-talk <core-talk at aps.anl.gov>]

I realize I forgot to CC the core-talk list.

On 11/9/22 06:51, Michael Davidsaver wrote:
> On 11/8/22 22:37, Kim, Kukhee wrote:
> > Hi  Michael,
> >
> > Thank you so much for your advice.
> > The multicast address is:  224.0.0.128
> Ah, right...  This address is used by PVA instead of something like caRepeater.
> It should only be sent via the loopback interface through.
>
> You can run "ip maddr" to see that 224.0.0.128 appears for the "lo" interface,
> but not for any others.
>
> > $ ip maddr
> > 1:      lo
> >         inet  224.0.0.128 users 2
> >         inet  224.0.0.1
> >         inet6 ff02::1
> >         inet6 ff01::1
> ...
>
>
> Are you seeing packets with this destination address actually going out on a wire?
>
>
> > We have PVA address setup as the followings:
> >
> > EPICS_PVA_ADDR_LIST='<broadcast addr for subnet>  255.255.255.255'
> > EPICS_PVA_AUTO_ADDR_LIST=NO
> > EPICS_PVA_BROADCAST_PORT=5076
> > EPICS_PVA_SERVER_PORT=507
> >
> > Hi Ernest and Mike,
> >
> > Can we capture the packet which goes to the multicast address to recognize searching or beacon?
> >
> > Thank you for your help.  I will update you.
> >
> > Thank you.
> > Best regards,
> > Kukhee
> >
> >
> >
> > ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> > *From:* Michael Davidsaver <mdavidsaver at gmail.com>
> > *Sent:* Tuesday, November 8, 2022 9:14 PM
> > *To:* Kim, Kukhee <khkim at slac.stanford.edu>
> > *Cc:* Zelazny, Michael Stanley <zelazny at slac.stanford.edu>; core-talk at aps.anl.gov <core-talk at aps.anl.gov>
> > *Subject:* Re: Question PVA environment variable
> > On 11/8/22 13:00, Kim, Kukhee via Core-talk wrote:
> > > Hi Everyone,
> > >
> > > We just realized that some of our servers send out packets to port 5076 in multicasting address.
> > What multicast address(es) are you seeing?
> >
> > Can you look (with packet capture) to see if these are
> > search or beacon messages?
> >
> >
> > > Since, the multicasting address is used for some of specific services, we would like to prevent the PVA, PVXS traffic to the multicasting address.
> > PVXS should not send any multicast traffic by default.
> > (we have no assigned addresses to use for PVA)
> >
> >
> > > Is there any PVA environment variables to control it?
> > https://mdavidsaver.github.io/pvxs/netconfig.html <https://mdavidsaver.github.io/pvxs/netconfig.html>
> >
> > There are a couple, all of the form EPICS_PVA*_ADDR_LIST
> >
> >
> > > Thank you so much for your help and support!
> > >
> > > Best regards,
> > > Kukhee
> > >
> > >
> > >
> > >
> > >
> > > Kukhee Kim | *Engineering Physicist *
> > >
> > > Advanced Controls Department
> > >
> > > SLAC National Accelerator Laboratory | Menlo Park, CA
> > >
> > > p: 650.926.4912 | m: 669.300.8192 | email: khkim at slac.stanford.edu