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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?

#41

Post by garganzol »

What the given article does not address is when to choose 10.x.x.x, 172.x.x.x and 192.168.x.x and why it's important to choose the right one.

Here is the prescribed solution:

- Use 10.x.x.x for office/enterprise LANs

- Use 192.168.x.x for home LANs

- Use 172.x.x.x for supplementary services like guest networks, DMZ etc

Why so? The reason is VPN.

When you connect to office VPN from home, you connect from 192.168.x.x to 10.x.x.x. This makes it very easy for routers to avoid address range clashes.

If you break that rule then you may end up with a weird situation when you connect from a home network 10.0.1.1/24 to an office network 10.0.1.1/24. Good luck trying to connect to that specific 10.0.1.12 machine: there is no easy way to determine where the packet should be routed.

Re: What's the history behind 192.168.1.1?

#43

Post by srj »

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.)

Sorry yes, you were right in saying 10.0/16.

Re: What's the history behind 192.168.1.1?

#44

Post by [deleted] »

garganzol wrote: post #41

What the given article does not address is when to choose 10.x.x.x, 172.x.x.x and 192.168.x.x and why it's important to choose the right one. Here is the prescribed solution: - Use 10.x.x.x for office/enterprise LANs - Use 192.168.x.x for home LANs - Use 172.x.x.x for supplementary services like guest networks, DMZ etc Why so? The reason is VPN. When you connect to office VPN from home, you connect from 192.168.x.x t…

[deleted]

Re: What's the history behind 192.168.1.1?

#45

Post by keshav_ »

garganzol wrote: post #41

What the given article does not address is when to choose 10.x.x.x, 172.x.x.x and 192.168.x.x and why it's important to choose the right one. Here is the prescribed solution: - Use 10.x.x.x for office/enterprise LANs - Use 192.168.x.x for home LANs - Use 172.x.x.x for supplementary services like guest networks, DMZ etc Why so? The reason is VPN. When you connect to office VPN from home, you connect from 192.168.x.x t…

what if I have two homes?

Re: What's the history behind 192.168.1.1?

#46

Post by forapurpose »

garganzol wrote: post #41

What the given article does not address is when to choose 10.x.x.x, 172.x.x.x and 192.168.x.x and why it's important to choose the right one. Here is the prescribed solution: - Use 10.x.x.x for office/enterprise LANs - Use 192.168.x.x for home LANs - Use 172.x.x.x for supplementary services like guest networks, DMZ etc Why so? The reason is VPN. When you connect to office VPN from home, you connect from 192.168.x.x t…

Hmmm ... it's easy to avoid clashes by choosing somewhat unique addressing schemes in those ranges.

For example, the 10. private network allows 255 different addressing schemes if you use a 16 bit subnet mask (10.0/16, 10.1/16, 10.2/16 .. 10.254/16), and ~64,000 schemes with an 24 bit subnet mask (10.0.0/24, 10.0.1/24, 10.0.2/24 .. 10.254.254/24). Just don't choose the common ones: 10.0/16, 10.0.0/24, 192.168/16, 192.168.0/24, etc.

Re: What's the history behind 192.168.1.1?

#47

Post by forapurpose »

keshav_ wrote: post #45
garganzol wrote: post #41

What the given article does not address is when to choose 10.x.x.x, 172.x.x.x and 192.168.x.x and why it's important to choose the right one. Here is the prescribed solution: - Use 10.x.x.x for office/enterprise LANs - Use 192.168.x.x for home LANs - Use 172.x.x.x for supplementary services like guest networks, DMZ etc Why so? The reason is VPN. When you connect to office VPN from home, you connect from 192.168.x.x t…

what if I have two homes?

Or if you are visiting someone else, you're in a cafe, a hotel ...

Re: What's the history behind 192.168.1.1?

#48

Post by anyfoo »

HighPlainsDrftr wrote: post #37

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 everythi…

What's a "bit boundary" in this context? And how does you subclassing scheme prevent wasted CPU cycles. at all?

Re: What's the history behind 192.168.1.1?

#49

Post by tinus_hn »

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…

For some reason courses that cover some networking used to make a huge point about the network classes for many years after CIDR made them completely irrelevant.
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