Wikipedia:Reference desk/Archives/Computing/2024 March 7

= March 7 =

Need an iphone user to take a quick look at this
This query, posted at 01:34, 7 March has been erroneously archived under 29 February. — Preceding unsigned comment added by 92.0.5.230 (talk) 18:25, 16 March 2024 (UTC)

What does it mean when a URL starts with numbers?
Is it an IP address? Example: http://24.75.48.45/website/sesssite/addisonlist.html

I found this URL on. Kk.urban (talk) 03:25, 7 March 2024 (UTC)


 * @Kk.urban, that's an IP address. It goes straight to the computer without using a Domain Name System (a sort of phone book for which IP address is behind a normal domain name).  You can look up the numbers using WHOIS to find out which Internet service provider currently has that IP address, e.g., at websites like https://www.whois.com/whois/24.75.48.45. WhatamIdoing (talk) 03:58, 7 March 2024 (UTC)
 * @WhatamIdoing If there is a website at an IP address, does that mean there has to be a domain name with letters and an extension like .com or .uk? Kk.urban (talk) 05:00, 7 March 2024 (UTC)
 * No, that's not actually a requirement (just good sense, because it's easier to remember a name than a string of numbers). WhatamIdoing (talk) 05:27, 7 March 2024 (UTC)
 * There are a number of services which you can use to do a "Reverse DNS lookup"; that is, to find any domain names that map to a given IP address. Google that phrase to find some of them. The particular IP address in the OP does not appear to have any domain name associated with it as far as I can tell. CodeTalker (talk) 07:05, 7 March 2024 (UTC)


 * Back in my day, all website addresses were numbers. 05:11, 7 March 2024 (UTC)
 * When was your day? The ARPA internet used host names in 1971. The earliest version of the IP protocol, using internet addresses with a fixed length of four octets (32 bits), is from 1980. --Lambiam 11:51, 7 March 2024 (UTC)


 * This is based on my memory of first using the Internet in 1994 or '95 was that every URL you went to was a four-octet number, not an alphanumeric name. Bubba73 You talkin' to me? 22:10, 7 March 2024 (UTC)


 * This was before the summer of 1994. At a terminal or dial-in connection you would Telnet to an IP address.  There you would see something like a Unix file structure.  Bubba73 You talkin' to me? 00:04, 8 March 2024 (UTC)
 * "" --Lambiam 09:09, 8 March 2024 (UTC)
 * The URI syntax includes URIs using an IP address (not just those with a domain name).
 * I remember File Transfer Protocol (FTP) being the most popular way to exchange files around 1990 (and that may be what @Bubba73 is remembering), and it could always, and often did, use the IP address. WhatamIdoing (talk) 19:11, 8 March 2024 (UTC)
 * I used what was available to me. I had to use a dial-in connection to a remote computer and then used telnet to get to the host, all in text mode.  I didn't have a browser until I got Netscape, which was after Window 95 came out. Bubba73 You talkin' to me? 00:45, 10 March 2024 (UTC)
 * So you used only numbers as website addresses, which is not the same as "all website addresses were numbers". Mosaic was released for Windows in June 1993, so if only you had heard of it (and were using Windows then) you could have enjoyed the wonders of the World Wide Web two years earlier. --Lambiam 16:29, 10 March 2024 (UTC)
 * I didn't say that all website addresses were numbers. I said that is all I knew of and used, at the time.That is what I remember, but my memory could be wrong.   I didn't have Windows (to run Mosaic) until some weeks or months after Windows 95 came out about June 1995. Bubba73 You talkin' to me? 01:55, 11 March 2024 (UTC)
 * When I reacted to what was presented as fact it was merely to keep the historical record straight. --Lambiam 15:41, 12 March 2024 (UTC)
 * I'm sorry for the confusion. I used the "back in my day" like an old person talking about their youth. In the first half of 1994 a woman (she is now my wife) taught me about the Internet.  She used a Unix workstation at work, so maybe numerical IP addresses were all she knew about.  That is all I knew for some time.  I had to dial in to a remote computer and use Telnet to get to the Internet.  There was no local number, so I had to call long distance, at a cost of about $0.10 per minute.  So I wasn't on very long each time and didn't explore it. Bubba73 You talkin' to me? 00:33, 14 March 2024 (UTC)


 * Telnet is different from WWW because it doesn't use URLs, but the telnet target can be either a domain name or an IP address. Often telnet is used to reach another machine in the same organization, and organizations often don't bother to set up a DNS server for internal machines, so that may be the origin of the perception that only IP addresses were used with telnet. DNS was certainly well established before 1994. Now if you want to reach back into history, when I started using email around 1979, we used bang paths. There was no Internet; each machine connected directly (usually via dialup) to a small list of other machines, and to reach a given destination you had to specify the exact sequence of machines that needed to be traversed to reach it. That was a real pain. CodeTalker (talk) 19:33, 8 March 2024 (UTC)


 * I don't see it mentioned, but there are many IP addresses that host services, such as web pages, without a host name. That is on purpose because the desire is to only make the services available to people who know about them. Further, they don't host the services on standard ports. Web pages are served on port 80. So, http://24.75.48.45 will go to that computer using port 80 (http = 80). But, to hide a web page, you would put it on something like port 514 and people would have to use http://24.75.48.45:514 to get to it. Further, DNS usually implies "Public" DNS. That isn't the only DNS. A group of people can set up a private DNS that only they use. Then, they can make up their own host names that nobody else has. For example, I could make bozo.xxx go to any IP address I like on my private DNS. I don't have to register it with a public registrar and pay for it (and hope it is available). Another example, wikipedia.org on public DNS goes to 200.80.154.224. But, I could setup a private DNS and send it to 24.75.48.45. Then, if you happened on one of my web pages and clicked a link to Wikipedia, you would use public DNS and go to the normal web page. I would click the same link and go to a different computer that may or may not have anything to do with Wikipedia. Why would anyone do this? It is commonly referred to by the blanket term "dark web." It is simply the Internet services that are not mapped to public DNS host names because they don't want it all to be public. 75.136.148.8 (talk) 12:05, 7 March 2024 (UTC)

There's a little bit of confusion creeping in here. the earliest naming system for ARPANET was the hosts file (originally hosts.txt). A unified hosts.txt was distributed from the Stamford Research Institute and contained all known names and addresses. By the early 1980s the file had become unwieldy and a team at Berkley developed the Berkley Internet Name domain (BIND) and the first Domain Name Service (DNS). the original hosts.txt exists on most machines to this day, but usually only contains the definition of the loopback and possibly the hosts own name. Having said which, for small networks it is still an easy way to define local fixed addresses. There are alternative DNSs to BIND which are designed for specific use cases. All DNSs should interoperate such that the local DNS will pass on requests it can't satisfy to an external DNS. This multilayered approach becomes essential when NAT or proxy servers are used such that the intranet address is not globally unique. — Preceding unsigned comment added by Martin of Sheffield (talk • contribs)