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Comment by danielvaughn | Hacker News Reader

I’ve always wanted to see something like a common port dictionary or encyclopedia. Just a big list of all the ports, each with their common usage and the history behind it.

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There's this wiki page that's pretty cool https://en.m.wikipedia.org/wiki/List_of_TCP_and_UDP_port_num...

Wikipedia's list is better than the official one because it explains what some of those protocols actually are – especially the early ones which don't have any RFC specified in IANA's registry.

Although, in several cases, there is an RFC, even though IANA's registry doesn't record it. For example, port 1 (tcpmux / TCP Port Service Multiplexer) uses a protocol defined by RFC1078, as Wikipedia's article on it helpfully explains – https://en.wikipedia.org/wiki/TCP_Port_Service_Multiplexer – but IANA's registry doesn't mention that.

Or similarly, port 5 is listed as rje / Remote Job Entry in the registry, but Wikipedia helpfully notes that it is the protocol defined by RFC407 (and maybe RFC725 is a newer version of it?). I doubt that ARPANET RJE protocol (whose syntax resembles FTP, SMTP, etc) ever saw any great amount of implementation; I believe historically the most popular RJE protocols were IBM's (2780/3780 and later Network Job Entry / NJE which was used in RSCS, most notably on BITNET) – but those protocols don't have an assigned port number, since they don't natively run on top of TCP/IP.

There are however some historical mysteries in this IANA registry for which even Wikipedia does not know the answer: the first of many is what ports 2 and 3, "compressnet", were used for. (Edit: What Wikipedia doesn't know, HN does: https://news.ycombinator.com/item?id=37016159

Seconded. I made some Anki cards out of the table of the "Well-known ports" table and it has proven surprisingly helpful fingertip knowledge for my kind of work (Linux systems and small scale networks in odd places).

Notably: port 666 - "Doom, the first online first-person shooter"

I'd like to see that email to IANA.

Nmap ships with an nmap-services file, which is a lot like /etc/services. However, you might find it interesting because it lists common worm backdoor ports rather than some obscure license server.

You can start with the IANA list [0]. You won't find posts like this listed but it should be a good place to start regardless.

[0]: https://www.iana.org/assignments/service-names-port-numbers/...

On Linux, /etc/services often contains a list of at least protocol names and numbers.

One fun list is in the default NetComm router software which still has a huge list of pre-saved port forwarding info for multiplayer PC Games that hasn't been updated since around 2001. That's quite a fun nostalgic list to browse.[1]

[1] Here's A-D: https://i.imgur.com/tCn2FBB.png

I mean if we wait long enough everything will be on port 443...

Questions from the distant future: "Why is there this hardcoded 16-bit field in the UDP header which is always 443? Why do we have an IPv6 header which is always followed by a UDP header which is always followed by a QUIC header? Why not just merge the three headers into one?"

And then RFC99999 defines a "new protocol" in which there is just a single header, which happens to have the same byte layout as IPv6+UDP+QUIC, with a bunch of fields like "reserved_01BB" which "always contains the bytes 0x01BB due to historical backward compatibility reasons"

> Why do we have an IPv6 header

Ah you’re an optimist I see

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