Which monitoring system has PUSH agents?

Question

linux

Hello!
tell me a monitoring system that can work with agents without interrogating them, but on the contrary, agents send it data about the system.
Answering the question why:
1) there are devices that are on the client's network with a bunch of firewalls, nats, etc. and there is no way to forward ports
2) there are devices with dynamic IP addresses (do not offer NOIP)
3) there are devices that do not always have a permanent connection Internet, so that the agent aggregates data for 5-10 hours (if there is no connection) and then sends them to the monitoring server
Preferably with windows and linux versions

Answer 1

Zabbix knows how to active agent

Answer 2

When there is no possibility of centralized collection/storage of data, the subjects of the system can also go offline one by one, blockchain-based solutions can help.
There are even ready-made ones: https://www.bitmessage.org/wiki/Main_Page
Through the CLI interface of that messenger, you can drive any serialized data between computers, without a server and without their simultaneous operation.