Hello Evgeny!
Thank you for reporting this issue.

Sadly, I was unable to reproduce the issue on 6.4.3. I created an Agent interface, and a "Simple check" type item. After creating the item I was still able to delete the interface from the host.
Could you please let me know more specifically what interface and what type of item did you create ?

Cheers,
Tom

1. I'm create a host without any interface:

2. After tham I'm add IPMI interface which can be deleted:

3. Link template to them:

4. Interface can't be deleted!

5. This template have only two items and one discovery with host prototype:

Hello Evgeny!
Thank you for this additional information!

Could you please also show the host prototype configuration ?

Cheers,
Tom

Hello, there is it:

with one external check:

Thank you for the information, Evgeny!

Could you please also let me know which Zabbix version you are experiencing this issue in ?

Cheers,
Tom

Hello, 6.4.3

Hello Evgeny!

I did some testing and I found out that items with item type "External check" create a dependency for an added IPMI interface. As soon as I removed the external check from the template that was linked to the host, I was able to delete the IMPI interface.

Thank you for reporting this issue!
Cheers,
Tom

Well, when creating the host do not add an IPMI interface.
At the end of the day this is nothing major, you can keep the IPMI interface for the time being as it does not interfere with your monitoring or decrease performance in any kind of way.

The issue will be fixed sometime in the future as I have confirmed this issue with out developer team and they will look into it.

Cheers,
Tom

Thanks, Tom!