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0 pointsasadhaider5y ago0 comments

Forgive me, I'm far from wearing a network hat and still struggle to wrap my head around things after 15 years. I don't know if this will make sense.

But seeing as the ISP uses NAT anyway, is there any way to further route the private ranges behind private ranges? I don't know if this is what 'Double NAT' is, I tried searching online to see if this would work or if it would cause all sorts of issues. I'm not too familiar with ISP Natting as my home ISP has always assigned a public IP address.

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4 comments · 4 top-level

paranoidrobot5y ago

I'm no ISP network engineer, but at a guess I'd probably look at splitting up customers into some sort of logical grouping (say per state or something) where they all sit behind the same CGNAT infra anyway, and give each of those their own 10/8.

wmf5y ago

Kludges like that are possible but it puts you into an even deeper circle of hell. The solution is probably something like 464XLAT.

parliament325y ago

Yes, you can keep NATting the same address space as many times as you want. As long as you have proper network boundaries there's nothing preventing, say, your ISP from using 10/8 for the country, then each province having a router that NATs 10/8 up to your gateway, which then NATs 10/8 for your home network.

But the further you go into the NAT layers the worse performance you'll see, because each NAT adds some latency overhead and more places where things can go wrong.

skykooler5y ago

Definitely. I've seen tethering implementations that put the tethered device on its own NAT, behind that of whatever network the host device is connected to.

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