OPC UA PubSub Traps And Pitfalls
From OPC Labs Knowledge Base
- Error "Unable to activate the adapter (...). Return code: -8"
- On Linux, elevated privileges are needed in order to send Ethernet packets. Run your program with sudo to resolve this issue.
- Error "Unable to load shared library 'libpcap' or one of its dependencies. ..."
- If you are on Ubuntu 18: Libpcap is "preinstalled", but SharpPcap won't find it. There are various ways how to resolve it. One of them is to create a copy of symlink /user/lib/x86_64-linux-gnu/libpcap.so.0.8 to symlink libpcap.so in the same directory.
- Subscriber does not receive anything, even when no filter is specified - but I am sure the publisher works.
- Check that you are publishing and subscribing on the intended network interface. On computers with multiple interfaces, which is now common, a default interface is chosen by the software when no interface is specified, and it may commonly be a wrong choice. In tools like OpcCmd or UADemoSubscriber, use the -ConnectionNetworkInterface (-cni) option. In subscriber code, set the InterfaceName of UAPubSubConnectionDescriptor.ResourceAddress.