Servers in a private network

peckaboo.com asks your server from the internet. A server that answers only inside a private network or behind a VPN cannot be connected yet.

Which addresses are refused

An address is refused when its name resolves only to addresses that are not public: a private network such as 10.0.0.0/8, 172.16.0.0/12 or 192.168.0.0/16, the loopback, a link-local address, or the metadata service of a cloud. peckaboo.com resolves the name itself and connects to the address it checked, so a name that points elsewhere later does not lead it into a private network either.

The form then says that it cannot reach a server at this address. It says the same when a name does not resolve at all or a connection fails, and never which part of the way failed.

Watching such a server today

To be watched, the server has to answer at a public https:// address. A reverse proxy that passes on only /healthz, /version and /metrics keeps the rest of the server private, and the metrics endpoint answers only with its token in any case. The proxy has to answer at the address itself: peckaboo.com does not follow a redirect.