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A comment on IPv6 may already be irrelevant – but so is moving off IPv4. Parent comment

Re:IPv6 may already be irrelevant – but so is moving off IPv4 by ReK_ on Wednesday October 23, 2024 @08:31AM (#41924350)
That's only true if you aren't behind CG-NAT. If you are, your firewall can port forward all it wants but it won't matter, the ISP would have to also port forward to you.
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Re:IPv6 may already be irrelevant – but so is moving off IPv4 by vetinari on Wednesday October 23, 2024 @08:34AM (#41924380)
Even in this situation, your ISP can port forward to you.

While not universal, some ISPs support PCP, where you can ask for a port mapping to your CGNAT-ed IP and port. They might or might not honor the external port (if it is taken, they obviously cannot), but you will get some hole punched.

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Re:IPv6 may already be irrelevant – but so is moving off IPv4 by doublerabbit on Wednesday October 23, 2024 @08:40AM (#41924452)
> your ISP can port forward to you

But will they? Domestic ISPs are pretty hesitant to offer such, or anything at that manner.

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Re:IPv6 may already be irrelevant – but so is moving off IPv4 by vetinari on Wednesday October 23, 2024 @08:44AM (#41924500)
Some do. But when they don't, it is not a fault of CGNAT - which does provide the capability -- but a fault of specific ISP, that's not willing to use it.
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