Hello,
In the context of bitcoinbackbone.org, we start some real-world networking test on mainnet.
As an indicative purpose, the user agent is the following “backbone-alpha:0.0.1”.
So far, we’re testing all the initial connection with v1 and v2 of the protocol and addr-related traffic (PING, ADDRV2, etc).
Yeah, if you see it appearing in your logs it’s likely it and I’m careful with experimentations on the network.