"Error connecting to the ZeroTier service" on Raspbian

[sq8l]

I’m using the latest Raspbian Lite on my RPi 3B. I’ve tried installing different versions of ZeroTier and compiling sources, but I’m always getting the same error when trying to use zerotier-cli:

Error connecting to the ZeroTier service:

Please check that the service is running and that TCP port 9993 can be contacted via 127.0.0.1.

The service is running, 127.0.0.1:9993 is open. Checked it with tcpdump (“tcpdump -i lo”) and it seems that there is some query packet sent (when running “zerotier-cli info”) and some response is also sent.
How to fix that?

edit: Also tried changing port number, but it didn’t help.

[sq8l]

Problem solved. It was caused by the IP masquerading (NAT) that was running. It was masking even the localhost address (127.0.0.1) with my local Ethernet address. Reconfiguring the masquerading solved the problem.