Re: Recsync: RecCeiver Server announcement contains Broadcast address instead of server ip address

[William Kirstaedter via Tech-talk <tech-talk@aps.anl.gov>]

I have a follow-up question in this matter.

as far as I understand, the recceiver takes the messages of the reccasters and stores them in an sqlite file.

how does the channelfinder java software access this information?

I'd like to run two instances of the recceiver and only one channelfinder.

it doesnt seem to be documented or I couldnt find it.

thanks in advance,

- W

William Kirstaedter (PP&B)	Fritz-Haber-Institut der MPG
Faradayweg 4-6	14195 Berlin
Tel: 030 8413 5405	Mail: kirstaedter@fhi-berlin.mpg.de

Am 25.04.2022 um 17:11 schrieb Michael Davidsaver:

> On
>       4/25/22 06:56, William Kirstaedter via Tech-talk wrote:
>       
> > TL;DR: it now works with Heinz'
> >         suggestion:
> >         
> >         
> >         longer explanation:
> >         
> >         
> >         we have multiple small labs with own, dedicated networks, that
> >         NAT outgoing traffic.
> >         
> >         but, all of them utilize the same private network: 10.0.0.0/23,
> >         since I set them up via script.
> >         
> >         
> >         so routing is not an option.
> >         
> >       
>       
>       I think this is only the case if you also lack administrative
>       control
>       
>       of both the IP routers involved.
>       
>       
>       
> > next idea was to translate the recceivers
> >         broadcast signal into the private lab network, via iptables,
> >         kind of a reverse NAT if you will.
> >         
> >         
> >         but as it turned out, iptables doesnt handle broadcast packets
> >         so I switched to socat which does.
> >         
> >       
>       
>       Maybe stating the obvious, but recceiver (like CA/PVA) can be
>       configured to send to unicast addresses.
>       
>       
>       So eg. the same tricks for routing CA searches / beacons will also
>       work with recsync.
>       
>       
> https://epics-controls.org/resources-and-support/documents/howto-documents/configure-channel-access/
>       
>       
>       In particular, when you have admin access on hosts, but not
>       routers, this can be
>       
>       a solution.
>       
>       
> https://epics-controls.org/resources-and-support/documents/howto-documents/channel-access-reach-multiple-soft-iocs-linux/
>       
>       
>       
> > since the reccasters in the IOCs only
> >         respond to the address in the 16byte message, the response never
> >         got through...
> >         
> >         
> >         but now, with the correct and dedicated IP of the channelfinder
> >         server in it, it works perfectly. :)
> >         
> >         
> >         by the way: FF FF FF FF as an IP address doesnt make sense to me
> >         anyways.
> >         
> >         in my eyes, the reccaster should either broadcast its first IP
> >         address or a configured one?
> >         
> >       
>       
>       Think about how this would work on a computer with multiple
>       network interfaces.
>       
>       You could end up with one IP in the recsync packet, and having the
>       OS put
>       
>       another in the IP header.  This used to happen with RSRV, and
>       caused problems
>       
>       with some network topologies.  The fix was to send 0xffffffff
>       instead of a
>       
>       specific IP.
>       
>       
>       
> >   - William
> >         
> >         
> >         William Kirstaedter (PP&B)     Fritz-Haber-Institut der MPG
> >         
> >         Faradayweg 4-6     14195 Berlin
> >         
> >         Tel: 030 8413 5405     Mail: kirstaedter@fhi-berlin.mpg.de
> >         
> >         
> >         Am 25.04.2022 um 13:01 schrieb Heinz Junkes via Tech-talk:
> >         
> > > Hallo Han,
> > >           
> > >           thanks for the hint. But this only works if the computer
> > >           system also has a “leg” (network connection)  into the
> > >           respective networks?
> > >           
> > >           
> > >           We also have something like this for the FEL network, for
> > >           example. But otherwise there are always gateway computers
> > >           between the individual experiment networks und the main-net.
> > >           
> > >           However, since we are routing out of the experiment machines
> > >           into our main-net, I'll try my hand at modifying announce.py.
> > >           
> > >           
> > >           tcpaddr='\xff\xff\xff\xff’ -> tcpaddr='\x8d\x0e\x8c\x62’ 
> > >           (141.14.140.98)
> > >           
> > >           
> > >           Heinz
> > >           
> > >           
> > >           
> > > > On 24. Apr 2022, at 02:43, Han
> > > >             Lee<jeonglee@lbl.gov>  wrote:
> > > >             
> > > >             
> > > >             Hi Heinz,
> > > >             
> > > >             
> > > >             Could you try to add your IOC address subnets into the
> > > >             recceiver server configuration as addr_list?
> > > >             
> > > >             
> > > > https://github.com/jeonghanlee/RecSync-env/blob/7b9fbc794ec8e4ae36349593780f9dcd00d142a0/site-template/recsync.conf.in#L16
> > > >             
> > > >             
> > > >             Multiple IOCs just see the resync server (Not CF -
> > > >             elasticsearch - server) without issues.
> > > >             
> > > >             
> > > >             For example, you can add each subnet where your IOCs are
> > > >             running, such as
> > > >             
> > > >             
> > > >             10.10.11.255:5049, 10.10.48.255:5049,
> > > >             ..................................
> > > >             
> > > >             
> > > >             I hope this is what you are looking for. Or I completely
> > > >             misunderstand your description.
> > > >             
> > > >             
> > > >             Best,
> > > >             
> > > >             Han
> > > >             
> > > >             
> > > >             
> > > >             On Fri, Apr 22, 2022 at 11:52 AM Heinz Junkes via
> > > >             Tech-talk<tech-talk@aps.anl.gov>  wrote:
> > > >             
> > > >             Hi,
> > > >             
> > > >             
> > > >             we need to route the announcements from our central
> > > >             Channelfinder server to a subnet so that the
> > > >             
> > > >             recasters on the IOCs in the subnet can send their PV
> > > >             information to the server.
> > > >             
> > > >             
> > > >             Unfortunately, the announcement package does not contain the
> > > >             IP of the server but FF:FF:FF:FF.
> > > >             
> > > >             
> > > >             root@priscilla:~# socat -ls -u -v -x
> > > >             UDP4-RECVFROM:5049,broadcast,fork,bind=141.14.143.255
> > > >             UDP4-SENDTO:10.0.1.255:5049,broadcast
> > > >             
> > > > > 2022/04/22 17:22:18.879313 
> > > > >               length=16 from=0 to=15
> > > > >               
> > > > >             
> > > >             52 43 00 00 ff ff ff ff 84 81 00 00 61 bf c1 23 
> > > >             RC..........a..#
> > > >             
> > > >             
> > > >             Gruss Heinz
> > > >             
> > > >             
> > > >             
> > > >             
> > > >             
> > > >             -- 
> > > >             Jeong Han Lee, Dr.rer.nat
> > > >             
> > > >             Staff Scientist and Engineer
> > > >             
> > > >             Lawrence Berkeley National Laboratory
> > > >             
> > > >             1 Cyclotron Road Mailstop 46R0161
> > > >             
> > > >             Berkeley, CA 94720, United States
> > > >             
> > > >             Tel :+1-510-486-6163
> > > >             
> > > >             Cell:+1-510-384-3868
> > > >             
> > > >           
> > >         
> >       
>       
>

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature