Steps to reproduce:

1. Setup an agent, a proxy and a server;
2. In agent configuration set "ServerActive" to IP of proxy;
3. Configure "Add host" autoregistration action;
4. Configure a host with:

• Host name = "Hostname" configuration of the agent;
• 2 interfaces, 1st with IP of agent, 2nd with some other IP;
• set 2nd interface as default;
• set Monitored by to Server;

1. Start server, proxy and agent.

Result:
After a while "Add host" autoregistration action will trigger and change values of the 2nd interface to be the same as in 1st.

Expected
Server should not perform any interface modifications that would result in duplicate interfaces.

Notes

• Based on comment. Issue introduced in 7.0.17 with removal of additional interface creation during autoregistration/discovery.
• The major change in 7.0.17 was that additional interfaces are no longer created and the interface set as default is updated instead. This happens at every trigger of "Add host" autoregistration action thus even after this fix, the only way to ensure an interface does not change it's value is to avoid setting it as default.