This is a valid ipv4 address • Hacker News Board

Re: This is a valid ipv4 address

#81

Post by jonpeda » Mon, Oct 21, 2013, 4:07 AM UTC

300bps wrote: post #77

jmillikin wrote: post #70

Earlier quoted context omitted.

> At best, you seem to be picking nits. More likely though > I think you just have a very surface level understanding > of what is going on here. You are replying to Rachel Kroll, and this quote is the networking equivalent of http://c2.com/cgi/wiki?KornShellStory

Oh, Rachel Kroll. You mean that Rachel Kroll? The one I've never heard of? Anyway, https://yourlogicalfallacyis.com/appeal-to-authority I don't care who someone is because I evaluate individual statements on their own merits. In Rachel's own statement, she just learned "why this worked" "the last time it came up on HN". I got my first modem in 1985 (have you noticed my username?) and been in IT for longer than most H…

The Korn Shell Story isn't an appeal to an authority, it's a punchline: Not only are you mistaken, the arrogance in your mistake is humorous to onlookers.

You can discuss whatever you like. What you can't do is make unsubtantiated claims about someone else's level of understanding, based on your inability to distinguish between what a specification says and what implementations do.

There are 2^32 strings of the form [0123]{16}. (16 base-4 digits) Does that mean that they are all valid IPv4 address? Can I type http://1230123012301230 into my browser and have it resolve?

And by the way, given the choice between "A investigated the phenomenon in detail recently" and "B has been interacting with the phenomenon for years without consideration for how it works", A is a more trustworthy source.

Re: This is a valid ipv4 address

#82

Post by einhverfr » Mon, Oct 21, 2013, 5:02 AM UTC

delinka wrote: post #41

alayne wrote: post #21

Earlier quoted context omitted.

It's just the decimal form of a base 256 number with four digits.

Or perhaps it's the decimal form of a base 16 number with eight digits.

Or perhaps it is the base 100 form of a base 2 number with 32 digits.

Re: This is a valid ipv4 address

#83

Post by throwawaykf » Mon, Oct 21, 2013, 5:05 AM UTC

nwh wrote: post #5

The decoded URL for this submission is http://184.172.10.74/ — the server for Hacker News. Here's some other encodings you can use for the same address, they're all valid and recognised by most browsers and other software: http://3098282570/ http://7393249866/ http://0xb8.0xac.0x0a.0x4a/ http://0270.0254.0012.0112/ The source for this comment is an XSS filtering bypass tool by RSnake — http://ha.ckers.org/xsscalc.htm…

More encodings:

http://[0:0:0:0:0:ffff:b8ac:a4a]

http://asdf:qwerty@3098282570/

http://asdf:qwerty@[0:0:0:0:0:ffff:b8ac:a4a]:80

(Might get a security/phishing warning on the last two links in some browsers.)

Re: This is a valid ipv4 address

#84

Post by kbenson » Mon, Oct 21, 2013, 5:20 AM UTC

nwh wrote: post #40

phaker wrote: post #39

Earlier quoted context omitted.

I use this one all the time: 127.0.0.1 == 127.1 10.0.0.1 == 10.1 192.168.0.1 == 192.168.1

I wasn't aware of that shortcut, that's very useful.

It's especially useful for some IPv6 addresses.

Re: This is a valid ipv4 address

#85

Post by SneManden » Mon, Oct 21, 2013, 6:07 AM UTC

phaker wrote: post #39

bdarnell wrote: post #25

Earlier quoted context omitted.

More weird formats (which at least work in chrome/mac, and the mac implementation of getaddrinfo()): http://184.11274826/ http://184.172.2634/ The rule here is that the last (but apparently only the last) numeric component may encode multiple bytes.

I use this one all the time: 127.0.0.1 == 127.1 10.0.0.1 == 10.1 192.168.0.1 == 192.168.1

I often use 0 == 0.0.0.0 == localhost

Re: This is a valid ipv4 address

#86

Post by ClashTheBunny » Mon, Oct 21, 2013, 7:47 AM UTC

SneManden wrote: post #85

phaker wrote: post #39

Earlier quoted context omitted.

I use this one all the time: 127.0.0.1 == 127.1 10.0.0.1 == 10.1 192.168.0.1 == 192.168.1

I often use 0 == 0.0.0.0 == localhost

This is not true. 0.0.0.0 may end up at localhost for you, but it's not localhost. I just get: PING 0.0.0.0 (0.0.0.0): 56 data bytes ping: sendto: No route to host

Which system do you use that this works on?

Re: This is a valid ipv4 address

#87

Post by simcop2387 » Mon, Oct 21, 2013, 7:58 AM UTC

jloughry wrote: post #51

dreen wrote: post #17

Guys check out this website at http://0x7f000001 hahaha what an idiot made this, that page is shit!

You made a good point here: I recognised 127.0.0.1 in the value instantly, showing that you can sometimes read this representation by eye, e.g.: 0x0a000001 = 10.0.0.1 0xc0a80001 = 192.168.0.1

That's why i usually like to go with, http://0x7f123456/ same effect but less recognition.

Re: This is a valid ipv4 address

#88

Post by escapologybb » Mon, Oct 21, 2013, 9:30 AM UTC

jmduke wrote: post #54

rmrfrmrf wrote: post #52

The fact that this is 'news' or a 'trick' to some people says a lot about the current state of HN. IP addresses have integer representations by design! Are the commenters here really so removed from actually doing work that they've never seen a database that stores IP addresses as integers? (Hint: ALL of the good ones do). That's to say nothing of the fact that there are clearly many people here who don't understand…

I haven't been on Hacker News long enough to speak definitively about the current state of HN (a bit less than two years, but I spent the first one lurking), but I would be more concerned about comments that complain about 'HN changing' (as someone who was on Reddit to hear complaints about all the Diggers... then all the 4chaners.. then all the high schoolers..) than content considered 'elementary' to smarter progra…

holds up hand

This totally confused me for a minute until I started reading the comments, what on earth does that say about my intellect?!

frets madly

Re: This is a valid ipv4 address

#89

Post by reidrac » Mon, Oct 21, 2013, 9:35 AM UTC

ClashTheBunny wrote: post #86

SneManden wrote: post #85

Earlier quoted context omitted.

I often use 0 == 0.0.0.0 == localhost

This is not true. 0.0.0.0 may end up at localhost for you, but it's not localhost. I just get: PING 0.0.0.0 (0.0.0.0): 56 data bytes ping: sendto: No route to host Which system do you use that this works on?

I don't know about the OP, but in Ubuntu Precise "ping 0" pings to 127.0.0.1.

I can't explain why.

Re: This is a valid ipv4 address

#90

Post by icoder » Mon, Oct 21, 2013, 9:39 AM UTC

throwawaykf wrote: post #83

nwh wrote: post #5

The decoded URL for this submission is http://184.172.10.74/ — the server for Hacker News. Here's some other encodings you can use for the same address, they're all valid and recognised by most browsers and other software: http://3098282570/ http://7393249866/ http://0xb8.0xac.0x0a.0x4a/ http://0270.0254.0012.0112/ The source for this comment is an XSS filtering bypass tool by RSnake — http://ha.ckers.org/xsscalc.htm…

More encodings: http://[0:0:0:0:0:ffff:b8ac:a4a] http://asdf:qwerty@3098282570/ http://asdf:qwerty@[0:0:0:0:0:ffff:b8ac:a4a]:80 (Might get a security/phishing warning on the last two links in some browsers.)

No warnings in Chrome