# OPCUA Communication Issue **URL:** \ **Category:** General Discussion\ **Tags:** ignition81\ **Created:** [April 29, 2025, 8:39pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706 "2025-04-29T20:39:36Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 29, 2025, 8:39pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/1 "2025-04-29T20:39:37Z")
Hi, I have two VM that I am try to communicate with via OPCUA client. One VM is hosting ignition while the other I have a python script that is trying to read and write tags to ignition. The issue I am having is that the OPCUA server in ignition is using the localhost IP address and not the IP address from the DHCP server. Can anyone let me know how this issue can be resolved? Thanks ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [April 29, 2025, 8:47pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/2 "2025-04-29T20:47:26Z")
The appropriate setting is found under Config =\> OPC UA =\> Server Settings =\> Endpoint Configuration. Change the Bind Addresses to `0.0.0.0` to listen on all interfaces. You will likely want to also change security settings. > **[Ignition's OPC UA Server | Ignition User Manual](https://www.docs.inductiveautomation.com/docs/8.1/ignition-modules/opc-ua/ignitions-opc-ua-server#opc-ua-server-settings)** > > Ignition's OPC UA server, provided by the OPC UA module, allows an ignition installation to utilize Ignition's various device driver modules. In addition, with the module installed, OPC UA clients can connect to Ignition's UA server, exposing any... Be aware that some hypervisors prevent VM to VM communications by default. ---
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 29, 2025, 9:03pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/3 "2025-04-29T21:03:05Z")
Hi, Thanks for your response I did set the binding to 0.0.0.0. See settings in the image. I am able to ping both VMs with no issue ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/7/b789d812a89933e5b8a01f2dde0f7089ef76759a.png) ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [April 29, 2025, 9:05pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/4 "2025-04-29T21:05:11Z")
Did you restart the gateway after changing the bind address? (It does not take immediate effect.) ---
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 29, 2025, 9:21pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/5 "2025-04-29T21:21:02Z")
Hi, I did but still got communication timeout. The IP address of my laptop is 192.168.XX.XX which I placed in the script. However, it is not working and I am not sure why? Just to let you know that I am new to ignition ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/f/9/f9728143d0d83962cd5057c859095e68f3b8b00f.png) ---
**Author:** ![David\_Stone](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/david_stone/32/79749_2.png) [@David\_Stone](https://forum.inductiveautomation.com/u/David_Stone)\ **Post date:** [April 29, 2025, 9:33pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/6 "2025-04-29T21:33:48Z")
I could be wrong here, but I have never seen URL based authentication on an OPCUA server. Especially at the discovery level. I would modify your script so it is using `opc.tcp://192.168.80.128:62541/discovery` ---
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 29, 2025, 9:39pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/7 "2025-04-29T21:39:19Z")
Hi, I made modification to my script and got the same results. See my script below ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/2/b/2be575414ff52f60ffbe0ede32f88b2615c29b1f.png) ---
**Author:** ![David\_Stone](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/david_stone/32/79749_2.png) [@David\_Stone](https://forum.inductiveautomation.com/u/David_Stone)\ **Post date:** [April 29, 2025, 9:40pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/8 "2025-04-29T21:40:56Z")
Have you opened the firewall on your Ignition server on port 62541? ---
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 29, 2025, 11:58pm UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/9 "2025-04-29T23:58:03Z")
> [@David\_Stone](#): > > opened the firewall on your Ignition server on port 62541 Hi, I added the port to the firewall. However, I got the error shown below ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/e/1/e165d046b6f93c5a049dae0b88d1d63590128118.png) ---
**Author:** ![David\_Stone](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/david_stone/32/79749_2.png) [@David\_Stone](https://forum.inductiveautomation.com/u/David_Stone)\ **Post date:** [April 30, 2025, 12:03am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/10 "2025-04-30T00:03:07Z")
Now you are getting somewhere, you are connecting to the server, but it is refusing your connection. Try removing the word 'discovery' from your URL. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [April 30, 2025, 12:03am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/11 "2025-04-30T00:03:27Z")
> [@David\_Stone](#): > > Try removing the word 'discovery' from your URL. I think it's probably the opposite - he doesn't have it but needs it. ---
**Author:** ![David\_Stone](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/david_stone/32/79749_2.png) [@David\_Stone](https://forum.inductiveautomation.com/u/David_Stone)\ **Post date:** [April 30, 2025, 12:04am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/12 "2025-04-30T00:04:07Z")
It's in the last screenshot he had. ---
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 30, 2025, 12:44am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/13 "2025-04-30T00:44:10Z")
Hi, Do you think that this error has to do with the trust certificate ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/1/615b2ae98a85fa49b32e0e218d7197ce1aaa0e89.png) ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [April 30, 2025, 12:47am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/14 "2025-04-30T00:47:32Z")
It doesn't. I missed the last screenshot and was looking at the one with the code. It means your client is trying to open a session against the discovery endpoint, which only supports the discovery services. This means your client isn't paying attention to the endpoint URLs that are returned by the GetEndpoints service. It looks like you're using the legacy python UA library instead of the supported asyncua library. I thought they had fixed this at some point. If not, you'll have to configure the Ignition OPC UA server to allow unsecured connections (change the Security Policies to `None, Basic256Sha256`) and then just point your client and the _non-discovery_ URL once the server has been restarted and allows unsecured connections. ---
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 30, 2025, 1:17am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/15 "2025-04-30T01:17:15Z")
Hi, when I change the security policies to none, Basic256Sha256 the server goes into fault. This is the setting I have for the server ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/7/6/76b00b3e68ab0955b1943eb2b2d30649b285353c.png) ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [April 30, 2025, 1:25am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/16 "2025-04-30T01:25:55Z")
Can you screenshot the server settings page where you changed the security policies? ---
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 30, 2025, 1:28am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/17 "2025-04-30T01:28:20Z")
Sure, is this what you are looking for ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/a/a/aa1779b6f2c935963cf0bfa34f87b1f38e2fabb6.png) ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [April 30, 2025, 1:31am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/18 "2025-04-30T01:31:59Z")
So you didn’t change anything then? ---
**Author:** ![David\_Brown](https://avatars.discourse-cdn.com/v4/letter/d/bb73d2/32.png) [@David\_Brown](https://forum.inductiveautomation.com/u/David_Brown)\ **Post date:** [April 30, 2025, 1:36am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/19 "2025-04-30T01:36:30Z")
I did but as soon as I changed the settings. The server went into fault ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/a/3a1444385aa41c48fd77e90ddec036917a3ce18b.png) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/e/4eaf82001616b11b946cdb183edc65b93f9a4beb.png) ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [April 30, 2025, 1:42am UTC](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706/20 "2025-04-30T01:42:54Z")
It seems you are changing settings on the OPC UA connection Ignition has to its own server, not on the server itself. You need to change the settings from the other screenshot. `None, Basic256Sha256` in the security policies setting. [Next page](https://forum.inductiveautomation.com/t/opcua-communication-issue/105706.md?page=2)