Gateway Network - Series configuration issues

Please refer to diagram below for reference.

A bit of explanation on the diagram.

  • 1a and 1b are gateways forming a redundant gateway pair. ‘a’ is master, ‘b’ is backup.
  • 2a and 2b are gateways forming a redundant gateway pair. ‘a’ is master, ‘b’ is backup.
  • 3 and 4 are independent gateways.
  • The arrows indicate how the gateway network connections are established.

Here’s the issue I’m running into:
I would like to have gateway 1 be able directly access the history, tags, and alarm providers running on gateway 4. As it stands:

  • Gateway 1 is able to talk to gateways 2 and 3.
  • Gateway 2 is able to talk to gateways 1, 3, and 4.
  • Gateway 3 is able to talk to gateways 1, 2, and 4.
  • Gateway 4 is able to talk to gateways 2 and 3.
  • All gateway network connections are configured to act as proxies.
    Gateway 1 is used as my primary Ignition server. It talks to all my PLCs, historizes the data, feeds the visual interface for operators, etc… I need to be able to configure a remote history provider on gateway 1 that is mapped directly to a history provider on gateway 4, so I can push history from gateway 1 to gateway 4 via a history tag splitter on gateway 1. Right now, I have to setup a history provider on gateway 3, push from gateway 1 to gateway 3, then have gateway 3 push to gateway 4. The same scenario will be true for the alarm provider. This will force me to procure an additional set of licenses for gateway 3, in addition to the historical provider and alarm provider licenses that will be necessary for gateway 4. All I need is gateway 1 and 4 to have those capabilities. Gateways 2 and 3 are only in the picture to act as gateway network proxies due to IT required network segregation rules I have to work with, but I can’t get gateway 1 to talk directly to gateway 4.
    Is that a gateway network limitation? Only meant to be able to talk to another gateway once or twice removed, but not thrice?
    I am running Ignition 7.9.9 on all those gateways.

I would appreciate any insight in the matter.

Yes, there’s a hardcoded 1 hop max. This limit will likely be removed in the future.

edit: may not be as simple as it being hardcoded, but the limitation does exist.

That’s a bummer, but thanks for getting me an answer on that.

Is the 1 hop max currently in place for v8.1?

I’m interested in making 2 hops with a remote tag provider and the same 2 hops with a remote history provider.

Starting with 8.1 you can set the max hops to 2 (or any other number, theoretically) by adding -Dignition.gan.maxproxydepth=2 to the “additional parameters” section of ignition.conf and restarting the gateway.

It may need to be set on the intermediate node as well as the originating node in your case. Somebody is going to get back to me with an answer on that…

1 Like

@ddonco Thank you for raising that question again.

I never thought I’d see the day. :partying_face:
This will help solve a number of constraints I’ve had to work around over the years.

@Kevin.Herron
For the benefit of those like me who know just enough to get themselves in trouble, is this the correct syntax that needs to be added to the ignition.conf file?

wrapper.java.additional=-Dignition.gan.maxproxydepth=2

You need to keep the numbers on the left side as well and make sure there are no duplicates.

As in

wrapper.java.additional.#=-Dignition.gan.maxproxydepth=2

where # is a unique number in the list of wrapper.java.additional statements?

Yeah, that’s right.

2 Things

  1. I was able to get a two proxy hop working. The proper syntax really helped. :grinning: Thanks for sticking with me.

  2. Following up on the original diagram, my tests seem to indicate that as long as gateway/proxy 2 is configured for 2 hops, then gateway 1 is able to see gateway 4. However, 4 can’t see gateway 1 until gateway/proxy 3 is configurated for 2 hops. It doesn’t look like the originating gateways need to have their ignition.conf files changed.