Greetings. I'm about to set up a small "secure" computer on the
internet, to hold various kind of data. I've chosen OpenBSD for it's
secure-oriented approach, and so on.
Besides the usual security advices (keep software patched, don't run
unnecessary services, monitor logs, and so forth) I'm looking for a way
to detect media change on a NIC.
The box is at a "secure" location but since I don't even trust the
provider, I was wondering how can I know if the network cable has been
unplugged.
Is syslog parsing the only way? (logging specific messages into a file,
monitor the file for changes)
Should I look at SNMP or other management stuff?

What I'm trying to avoid is the provider removing the cable or taking
the interface down switch-side, even for a second. I have my own
reasons, so let us not talk about "why".

thanks in advance