7 ms·

I consider FTP as most funky of oldschool protocols due to 2 TCP ports used (ftp-data 20/tcp, ftp 21/tcp).

by voytec 3y ago

smokel 3y ago
The list of TCP and UDP port numbers [1] is a treasure trove of historical artefacts. It's amazingly hard to find information on e.g. "compressnet", which is wasting port 2 and port 3 for eternity. [1] https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbe...
- deleted 3y ago
  [deleted]
- voytec 3y ago
  Available also at /etc/services or %SystemDrive%\%SystemRoot%\System32\drivers\etc\services id Software's Doom having port 666 (unofficially) assigned is a nice touch.
  - teddyh 3y ago
    Actually official list: <https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml https://www.iana.org/assignments/service-names-port-numbers/...>
  - bayindirh 3y ago
    Another similar trivia is present in PCI-IDs. Intel got 8086 for themselves. Some other notable examples: Broadcom/LSI: 1000 Motorola: c0de Chrysalis-ITS: cafe Blackmagic bdbd Indigita Corporation dead Middle Digital Inc. deaf Elcus e1c5 Eagle Tech ea01 Essence Tech e55e Echo ecc0 Daiblo Tech db10 Canny Edge caed CACE Tech cace There are many more examples, but it's enough, I think. If you want to dive, source: https://pci-ids.ucw.cz/ https://pci-ids.ucw.cz/
- ta988 3y ago
  There is this magazine ad about it: Network World Sep 16, 1991 page 5 https://books.google.com/books?id=Ww0EAAAAMBAJ&pg=PA4&dq=compressnet&hl=en&sa=X&ved=2ahUKEwjEqq6pk8eAAxWwjYkEHQraD-wQuwV6BAgJEAY#v=onepage&q=compressnet&f=false https://books.google.com/books?id=Ww0EAAAAMBAJ&pg=PA4&dq=com...
  - NelsonMinar 3y ago
    I was skeptical at first but found evidence to corroborate it's the same thing, the key fact being the company named Process Software. The reference in RFC1340 for it says "Bernie Volz" of process.com. Searching on that let me to a Web-0.9 style page with the text "compressnet/tcp is a protocol that is used to compress TCP connections for WANS. It used two ports to compress tcp conections, one to send the compressed TCP connection data through, and one used for the management of CompressNet. This is a commercial product only." https://donsnotes.com/tech/networks/internet/proto/compressnet.html https://donsnotes.com/tech/networks/internet/proto/compressn...
- b112 3y ago
  Some of the tcp headers are the same. Bits for companies I can barely find info about
wkat4242 3y ago
Yeah and the server connecting to the client for a transfer is kinda weird too. Of course there's passive mode these days.
- dfawcus 3y ago
  It was always there...
jgtrosh 3y ago
A nice post about the weirdness of FTP: https://computer.rip/2020-05-20-file-transfer-pseudoprotocol.html https://computer.rip/2020-05-20-file-transfer-pseudoprotocol...
- voytec 3y ago
  Even funkier! > FTP was historically allocated ports 20, 21, and 22.
akikoo 3y ago
http://slacksite.com/other/ftp.html http://slacksite.com/other/ftp.html (my brother was an aminet maintainer at nic.funet.fi in the 90s :)
tssva 3y ago
It is much more complicated than using two ports. There are two modes of ftp, active and passive. In active mode the client connects to the server on port 21. It then issues a PORT command which tells the server which port on the client to connect to for data. The server connects to destination port on the client using port 20 as the source port. In passive mode the client connects to the server on port 21 and issues the PASV command. The server chooses a random port for data and responds back to the client with a PORT command indicating this port. The client then connects to this destination port on the server using a random high port as the source port.
Ekaros 3y ago
It is not bad design. At least in world without firewalls or NATs. It potentially allows things like one machine setting up file transfer between two servers. Not sure if this was done, but could be done. Lot of stuff was rather interesting design, which we really have gotten away with how our current networks are build. Like multi and broadcasting for actual content.
- dfawcus 3y ago
  "It potentially allows things like one machine setting up file transfer between two servers. Not sure if this was done, but could be done." Well I certainly recall doing it back in the 90s. I vaguely recall it was sending PASV to one server, taking its response values, and providing them in a PORT command to the other server. Then sending the RETR and STOR commands respectively to the two servers.

I consider FTP as most funky of oldschool protocols due to 2 TCP ports used (ftp-data 20/tcp, ftp 21/tcp).

by voytec 3y ago

I consider FTP as most funky of oldschool protocols due to 2 TCP ports used (ftp-data 20/tcp, ftp 21/tcp).

The list of TCP and UDP port numbers [1] is a treasure trove of historical artefacts. It's amazingly hard to find information on e.g. "compressnet", which is wasting port 2 and port 3 for eternity. [1] https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbe...

deleted 3y ago
[deleted]
voytec 3y ago
Available also at /etc/services or %SystemDrive%\%SystemRoot%\System32\drivers\etc\services id Software's Doom having port 666 (unofficially) assigned is a nice touch.
- teddyh 3y ago
  Actually official list: <https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml https://www.iana.org/assignments/service-names-port-numbers/...>
- bayindirh 3y ago
  Another similar trivia is present in PCI-IDs. Intel got 8086 for themselves. Some other notable examples: Broadcom/LSI: 1000 Motorola: c0de Chrysalis-ITS: cafe Blackmagic bdbd Indigita Corporation dead Middle Digital Inc. deaf Elcus e1c5 Eagle Tech ea01 Essence Tech e55e Echo ecc0 Daiblo Tech db10 Canny Edge caed CACE Tech cace There are many more examples, but it's enough, I think. If you want to dive, source: https://pci-ids.ucw.cz/ https://pci-ids.ucw.cz/
ta988 3y ago
There is this magazine ad about it: Network World Sep 16, 1991 page 5 https://books.google.com/books?id=Ww0EAAAAMBAJ&pg=PA4&dq=compressnet&hl=en&sa=X&ved=2ahUKEwjEqq6pk8eAAxWwjYkEHQraD-wQuwV6BAgJEAY#v=onepage&q=compressnet&f=false https://books.google.com/books?id=Ww0EAAAAMBAJ&pg=PA4&dq=com...
- NelsonMinar 3y ago
  I was skeptical at first but found evidence to corroborate it's the same thing, the key fact being the company named Process Software. The reference in RFC1340 for it says "Bernie Volz" of process.com. Searching on that let me to a Web-0.9 style page with the text "compressnet/tcp is a protocol that is used to compress TCP connections for WANS. It used two ports to compress tcp conections, one to send the compressed TCP connection data through, and one used for the management of CompressNet. This is a commercial product only." https://donsnotes.com/tech/networks/internet/proto/compressnet.html https://donsnotes.com/tech/networks/internet/proto/compressn...
b112 3y ago
Some of the tcp headers are the same. Bits for companies I can barely find info about

wkat4242 3y ago

Yeah and the server connecting to the client for a transfer is kinda weird too. Of course there's passive mode these days.

dfawcus 3y ago
It was always there...

jgtrosh 3y ago

A nice post about the weirdness of FTP: https://computer.rip/2020-05-20-file-transfer-pseudoprotocol.html https://computer.rip/2020-05-20-file-transfer-pseudoprotocol...

voytec 3y ago
Even funkier! > FTP was historically allocated ports 20, 21, and 22.

akikoo 3y ago

http://slacksite.com/other/ftp.html http://slacksite.com/other/ftp.html (my brother was an aminet maintainer at nic.funet.fi in the 90s :)

tssva 3y ago

It is much more complicated than using two ports. There are two modes of ftp, active and passive. In active mode the client connects to the server on port 21. It then issues a PORT command which tells the server which port on the client to connect to for data. The server connects to destination port on the client using port 20 as the source port. In passive mode the client connects to the server on port 21 and issues the PASV command. The server chooses a random port for data and responds back to the client with a PORT command indicating this port. The client then connects to this destination port on the server using a random high port as the source port.

Ekaros 3y ago

It is not bad design. At least in world without firewalls or NATs. It potentially allows things like one machine setting up file transfer between two servers. Not sure if this was done, but could be done. Lot of stuff was rather interesting design, which we really have gotten away with how our current networks are build. Like multi and broadcasting for actual content.

dfawcus 3y ago
"It potentially allows things like one machine setting up file transfer between two servers. Not sure if this was done, but could be done." Well I certainly recall doing it back in the 90s. I vaguely recall it was sending PASV to one server, taking its response values, and providing them in a PORT command to the other server. Then sending the RETR and STOR commands respectively to the two servers.