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What's the history behind 192.168.1.1?

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Re: What's the history behind 192.168.1.1?

#31

Post by WalterGR »

egwynn wrote: post #6
insickness wrote: post #2

This explains the reason private ranges were designated but not why 192.168.0.0 in particular within the Class C range was designated to be private. Does anyone know why that number in particular was chosen?

Found this link in one of the responses on that page: https://superuser.com/questions/784978/why-did-the-ietf-spec... Similarly, I expect Postel picked 192.168 because, at the time he made the choice, it was the next available, or nearly the next available, network to be assigned from the former Class C space. This probably can't be proved one way or the other, but the pace of address assignments shown in the RFCs st…

Text formatted as code on HN is very difficult to read when on mobile. Using italics or > to quote things is better.

Similarly, I expect Postel picked 192.168 because, at the time he made the choice, it was the next available, or nearly the next available, network to be assigned from the former Class C space. This probably can't be proved one way or the other, but the pace of address assignments shown in the RFCs strongly suggests that they would have been in this general vicinity around 1993-1994 when the assignments were made. (Addresses in 192.159 were being assigned in 1992. No dates are available for assignments in 192.160-192.167 as these were at some point reallocated to RIPE.)

Re: What's the history behind 192.168.1.1?

#32

Post by srj »

forapurpose wrote: post #28
6t6t6t6 wrote: post #10

Something I never understood is why people choose 192.168.1.1 for private networks. Being all the other factors equal, isn't 10.1.1.1 easier to type and more "aesthetically pleasant"?

> Something I never understood is why people choose 192.168.1.1 for private networks While interviewing someone for an entry-level job, I told the interviewee that there was a network using 10.0/16 (a 16-bit subnet mask, or more popularly 10.0.x.x). He corrected me and said that 10.0.0.0 networks should have an 8 bit subnet mask (10.x.x.x). On one hand, I definitely liked that he was willing to challenge me, even dur…

10/8 is a class A range (high order bit = 0), but CIDR says that you can separately describe which bits are for the network. Unless this interview was conducted more than 20 years ago I'd say your interviewer was mistaken.

Re: What's the history behind 192.168.1.1?

#33

Post by srj »

derekp7 wrote: post #25

I wish there was a netblock reserved for packets that never leave a physical (or virtual) host, that could be used for the default internal network for things like Docker. In my case, Docker defaulted to 172.17.0.0/16, which happened to conflict with one of the IP ranges for my wing of the building at work. I've resorted to using RFC 5737 (test-net-1 through 3) IP ranges for this purpose, even though that isn't what…

127/8 exists for this purpose. IPv6 funny enough went conservative here and only has a single address, ::1/128.

Re: What's the history behind 192.168.1.1?

#34

Post by forapurpose »

srj wrote: post #32
forapurpose wrote: post #28

Earlier quoted context omitted.

> Something I never understood is why people choose 192.168.1.1 for private networks While interviewing someone for an entry-level job, I told the interviewee that there was a network using 10.0/16 (a 16-bit subnet mask, or more popularly 10.0.x.x). He corrected me and said that 10.0.0.0 networks should have an 8 bit subnet mask (10.x.x.x). On one hand, I definitely liked that he was willing to challenge me, even dur…

10/8 is a class A range (high order bit = 0), but CIDR says that you can separately describe which bits are for the network. Unless this interview was conducted more than 20 years ago I'd say your interviewer was mistaken.

> I'd say your interviewer was mistaken

Is that what you meant to say? The interviewer (me) thought that 10.0/16 was fine, which I think agrees with your analysis. The interviewee said only 10/8 was correct.

(Re-reading my GP comment I realize that my role might have been ambiguous, so I've clarified it.)

Re: What's the history behind 192.168.1.1?

#35

Post by HighPlainsDrftr »

forapurpose wrote: post #34
srj wrote: post #32

Earlier quoted context omitted.

10/8 is a class A range (high order bit = 0), but CIDR says that you can separately describe which bits are for the network. Unless this interview was conducted more than 20 years ago I'd say your interviewer was mistaken.

> I'd say your interviewer was mistaken Is that what you meant to say? The interviewer (me) thought that 10.0/16 was fine, which I think agrees with your analysis. The interviewee said only 10/8 was correct. (Re-reading my GP comment I realize that my role might have been ambiguous, so I've clarified it.)

If you said 10/24, I'd immediately think 10.0.0.0/24. 10/8 would certainly be valid. 10.0/16 is too.

I remember when CIDR came around back in the 90's. Man people were pissed off when you would call out a 'Class A/B/C/D/E' block. I prefer to always be specific when writing my CIDR. I understand when people don't do it.

Be liberal in what you accept and conservative in what you send.

Re: What's the history behind 192.168.1.1?

#36

Post by HighPlainsDrftr »

adzm wrote: post #23
jorvi wrote: post #21

Earlier quoted context omitted.

It depends. Some use 10.0.0.x, some use 192.168.1.x and some use 192.168.178.x There's also 172.16.0.x, which I have never seen used by default on any networking devices.. which makes it perfect if you have a piece of network that you visibly want to separate from the rest of the LAN.

I use 172.16.0.0/12 for that reason, to differentiate it from other subnets when using VPNs.

I almost always put my VPN connections in this range for that reason. Nobody ever uses it. Makes it obvious when you see that address in a webserver log or a route table.

Re: What's the history behind 192.168.1.1?

#37

Post by HighPlainsDrftr »

Up until 4 years ago, I used to always allocate addresses specifically on bit boundaries. I did this mainly for one reason - aligning the bytes and trying not to waste CPU cycles.

For example, in a /24 network: 0-15 - network equipment 16-31 - some special gear 32-63 - mail servers or something like that 64-127 - split it up and align more things 128-191... you get the point.

... The ultimate goal was to hit everything on a bit boundary so the CPU wouldn't work so hard

These days, CPU power is so prominent, it doesn't matter. DHCP is probably the way to go.

IPv6 is here. We have the opportunity to really make CPU's fast again with IPv6!

Re: What's the history behind 192.168.1.1?

#38

Post by y4mi »

y4mi wrote: post #29
derekp7 wrote: post #25

I wish there was a netblock reserved for packets that never leave a physical (or virtual) host, that could be used for the default internal network for things like Docker. In my case, Docker defaulted to 172.17.0.0/16, which happened to conflict with one of the IP ranges for my wing of the building at work. I've resorted to using RFC 5737 (test-net-1 through 3) IP ranges for this purpose, even though that isn't what…

Uuh, 127.0.0.1 never leaves the physical machine. It's also a full subnet, so 127.0.0.254 would work as well. Dockers main usecase just isn't purely internal, do using that ip range wouldn't make any sense

Too late to edit my message, so I'll use a response instead. Docker rebinds the 127 network to each container, so you cant - by default - communicate through these IP Addresses.

An easy fix could be to just let the container use the hosts network stack (so, not network type: bridge). After that, you can bind the daemons to specific IP Addresses in the subnet - i.e. 127.0.0.2:3306 DB1 127.0.0.3:3306 DB2 and they'll be able to communicate directly.

But as mentioned before: this is not the primary usecase for docker, so its cumbersome to use.

Re: What's the history behind 192.168.1.1?

#39

Post by 6t6t6t6 »

forapurpose wrote: post #28
6t6t6t6 wrote: post #10

Something I never understood is why people choose 192.168.1.1 for private networks. Being all the other factors equal, isn't 10.1.1.1 easier to type and more "aesthetically pleasant"?

> Something I never understood is why people choose 192.168.1.1 for private networks While interviewing someone for an entry-level job, I told the interviewee that there was a network using 10.0/16 (a 16-bit subnet mask, or more popularly 10.0.x.x). He corrected me and said that 10.0.0.0 networks should have an 8 bit subnet mask (10.x.x.x). On one hand, I definitely liked that he was willing to challenge me, even dur…

10.0.0.0/8 is correct, you can only use the last 24 bits. But nothing prevents you from breaking this class A in smaller networks!

That means that you can not use 10.0.0.0/7 (which would include 11.0.0.0) but you can use 10.0.0.32/30, that includes from 10.0.0.32 until 10.0.0.35.

Re: What's the history behind 192.168.1.1?

#40

Post by forapurpose »

HighPlainsDrftr wrote: post #35
forapurpose wrote: post #34

Earlier quoted context omitted.

> I'd say your interviewer was mistaken Is that what you meant to say? The interviewer (me) thought that 10.0/16 was fine, which I think agrees with your analysis. The interviewee said only 10/8 was correct. (Re-reading my GP comment I realize that my role might have been ambiguous, so I've clarified it.)

If you said 10/24, I'd immediately think 10.0.0.0/24. 10/8 would certainly be valid. 10.0/16 is too. I remember when CIDR came around back in the 90's. Man people were pissed off when you would call out a 'Class A/B/C/D/E' block. I prefer to always be specific when writing my CIDR. I understand when people don't do it. Be liberal in what you accept and conservative in what you send.

Yes, Postel's advice applies to many things.

I think there is some misunderstanding. The question wasn't the notation but the subnetting. See the story in the GGP.

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