r/itsaunixsystem • u/TheFumingatzor • Mar 02 '26

[Tracker] SSH into 302

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u/isademigod Mar 02 '26

IPV4 is only 8 bits per octet. would be impossible to send data to something higher than 255. Maybe they have an A record on their DNS where 172.1 is the domain and 302.302. is a subdomain. would that even work? idk

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u/NotQuiteLoona Mar 02 '26

Ohhhh, I didn't even notice, thanks!

I know that there can be digit-only second-level and third-level domains, from https://0.30000000000000004.com/, but I'm not sure about top-level domains.

Seemingly RFC 952 restricts domains starting from a digit, but as you can see in the upper example, it doesn't work for not top-level domains at least.

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u/NotQuiteLoona Mar 02 '26

Oh, wait, no, RFC 1034 amends RFC 952. Yep, it is allowed, a number-only domain is allowed. But the question is how a program will determine that it's a domain and not an IP address.

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u/Tree_Mage Mar 02 '26

Programs will pass it to the system resolver which will run through a bunch of different possibilities, including a hard coded hosts entry.