RE: Identical Process Variable names on Multiple Servers

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

Sorry I think I may have left out part the IPs are for example 192.168.1.40 and 192.168.2.50.  They exist on different subnets and I didn’t have trouble at first running one IOC on say 192.168.1.40 and having 192.168.2.50 be the client doing caget/camonitor. 

 

I have the client(192.168.2.50) env variable CA_ADDR_LIST=192.168.1.40 and it was working fine but now that I have switched things up and I have 192.168.1.40(CA_ADDR_LIST=192.168.2.50) be the client and 192.168.2.50 have the single IOC running it doesn’t seem to want to communicate. 

 

Which led to me believe I might have just gotten lucky before when it was working and I am missing a piece of the puzzle such as using cagateway or like you have mentioned broadcast addressing.  When you stated to set both to the same broadcast address, do you mean that 192.168.1.40 machine would have 192.168.2.255 and the 192.168.2.50 machine would have 192.168.1.255 set under CA ADDR_LIST respectively.

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Ralph Lange via Tech-talk
Sent: Thursday, February 18, 2021 8:26 AM
To: EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: Re: Identical Process Variable names on Multiple Servers

 

On Thu, 18 Feb 2021 at 16:14, Michael Davidsaver <mdavidsaver at gmail.com> wrote:

On 2/18/21 7:01 AM, Ralph Lange via Tech-talk wrote:
> When using an explicit IP for the name search, only the /last/ IOC started on that machine will answer.

FYI. first vs last depends on host OS, and as I recall windows and linux differ.

 

Hm! I was not aware of that at all. Will verify and update the README.

 

2. mis-configured broadcast address

Both the .1 and .2 host must have the same broadcast address set.

 

As .1 and .2 are different networks, it actually depends on the structure.

 

Always: The broadcast addresses must match between the IOC host (receiving the broadcast) network configuration and the client (sending the broadcast) ADDR_LIST setting.

If the client host has a network interface into the IOC host network: The client host network configuration on that interface must also match.

If there is a switch between the two networks: The switch needs to be configured to forward "directed broadcasts".

 

Cheers,
~Ralph