> But maybe the local network interface is down, maybe there's a local firewall rule blocking it,...

That's exactly why you log it as a warning. People get warned all the time about the dangers of smoking. It's important that people be warned about smoking; these warnings save lives. People should pay attention to warnings, which let them know about worrisome concerns that should be heeded. But guess what? Everyone has a story about someone who smoked until they were 90 and died in a car accident. It is not an error that somebody is smoking. Other systems will make their own bloody decisions and firewalling you off might be one of them. That is normal.

What do you think a warning means?