Subj : Re: Just how big is IPv6?
To   : Deon George
From : Warpslide
Date : Wed Dec 25 2024 09:24:06

On 24 Dec 2024, Deon George said the following...

 DG> I use /112's and /88's a lot...

I've been playing around with subnetting IPv6 here, my ISP gives me one /64 by default (18,446,744,073,709,551,616 or 18.4 quintillion usable host addresses).

I also discovered if I set my wan interface to request a /48 they'll give me one of those as well.  A /48 has 65,536 /64 subnets.

I initially tried setting my config to request a /62 (4 /64s) and /61 (8 /64s) but it didn't seem to work, not sure if its my EdgeRouter 4 or my ISP that doesn't support them but a /48 works fine.

This is when I started doing some reading on just how many addresses are available in IPv6.  I was initially concerned about hoarding 
1,208,925,819,614,629,174,706,176 (1.2 septillion) addresses, and for some reason still am, probably just "old" thinking.  1.2 septillion addresses is a mere 0.0000000000000036% of the total IPv6 address space.  Numbers this big really boggle (my|the) mind.

I have 4 vlans here at home, each of them has their own /64 (with 65,532 other /64s just waiting to be allocated).

I could try slicing up one /64 into 4 /66s or something, not sure if my router supports that, but could be a fun exercise to try and see what happens.  I suppose I really don't need to be concerned with hoarding/wasting such a "small" number of addresses.


Jay

.... Some of the crowd have decided to voice their opinion by staying away

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