It might be the telnet filtering in action. The host responds to ping but I get nothing back on TCP/23, not even a reset.

I connected a few times today to the IPv4 one. Have had no problems myself.

The manufacturer should at least supply certificates, and it could be up to you to ignore or use. It's not much but it's something.

CA compromise is very rare and difficult. There are much easier attacks on TLS than that (notably, attacking insecure validation methods; the problem isn't that CAs aren't secure, it's that validation methods and their dependencies are insecure). Besides, the CAs for TLS only covers transport security; authentication+authorization would be handled securely through OIDC, using temporary sessions and not exposing the true credential, often combined with 2FA. Even you successfully attack a TLS server, two factors, and an active session, it only works once; you have to keep pulling it off to remain inside.

Compare that to malware that just copies a developer's ssh private key off the disk (again, almost nobody ever password protects theirs). This just happened recently on a massive scale with the npm attacks. Or intercepts the first connection from a client host and, again, because nobody ever validates keys, injects a false host key, and now they're pwnd indefinitely. Or, again, companies that do not strictly validate host keys, meaning immediate MitM. There's like a dozen ways to compromise SSH. It doesn't have to be that way, but it is that way, because of how people use it.

SSH certs aren't TLS certs. Totally different format. All SSH CAs are private, you run your own CA to issue certs to devices you want to allow to connect to your server.

>>Nobody verifies host keys,

>The known_hosts file is verification of host keys

I think the point was that those devices typically generate host keys dynamically and therefore the host key verification is usually turned off, leaving you just with encryption (which is still better than telnet - at least you're safe against passive adversaries). At least that's what I've seen in practice.

TIL that IPsec can be used without encryption. That should work pretty well.

Telnet is mostly used for auth and straightforward terminal/BBS access in my experience. There are some other alternatives like HamSSH but I don’t think it’s that common.

Yes but in many ways it's riskier to do that when you have a license from them.

In general, this is pretty true in practice.

Just dont mess with: GPS, Airline radio, cell phones, broadcast infra, emergency services

If you're blowing double the power for ISM, nobody cares. Your PEP using a yagi is 4x what is legal? Unless you piss off a ham, nobody cares.

And even if you are a ham, and are using 150KHz bandwidth with low power in, say 50MHz (regulation says 40KHz max), again, nobody cares.

And also if above 6GHz (common SDR top end), nobody will notice. The equipment up there is $$$$$.

But damn, you want to piss off hams? Mention bitrate maximums or encryption. You'll never hear the end from the old gatekeeping idiots.

For a few weeks I ran a MUD over AX.25 for a couple of my friends.

Because on their own, MUDs aren't nerdy enough, amateur radio isn't nerdy enough, and indeed packet radio isn't nerdy enough.

Eventually we decided we'd had our fun and now I needed to the TNC for something else.

TBH, I don’t care if someone drop all my inventory and delete my account. If I would care about it then I would obviously not use telnet.

Ah, not really. We are on a non-standard port (9000). I just meant some folks use the telnet client to connect, and we do negotiate some telnet options. I use tintin++ these days but I think most of our players are still using decades old zMUD versions to connect!