Need clarification on UDP Broadcasting to multiple IOCs on same PC

["Manoussakis, Adamandios via Tech-talk" <tech-talk at aps.anl.gov>]

Hello All,

 

I have been trying to understand the UDP broadcast requests when having multiple IOCs running on a single host (ubuntu).  I am using the script from https://wiki-ext.aps.anl.gov/epics/index.php/How_to_Make_Channel_Access_Reach_Multiple_Soft_IOCs_on_a_Linux_Host and the rule is in place on my host:    0     0 DNAT       udp  --  any    any     anywhere             ubuntu               udp dpt:5064 to:192.168.252.255.  My confusion comes from that when I hook up wireshark to my local interface I am seeing traffic from caget requests but don’t seem to see the broadcast going out (192.168.252.255:5064).  The rule seems like any source traffic pointed at my hostname should get funneled to the broadcast address.

 

I am running into an issue with my gateway where the gateway is not able to reach all the IOCs but without the gateway it seems to work with the 10 IOCs I have running.  But now I am not so sure its due to the prerouting rule and might be some other magic happening?

 

Thanks,
Adam