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<== Date ==> | <== Thread ==> |
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Subject: | Re: Need clarification on UDP Broadcasting to multiple IOCs on same PC |
From: | Ralph Lange via Tech-talk <tech-talk at aps.anl.gov> |
To: | EPICS Tech Talk <tech-talk at aps.anl.gov> |
Date: | Tue, 7 Dec 2021 19:45:49 +0100 |
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?