4 ms·

It is not true that an ISP cannot give each customer just a single IPv6 address. The Linux box I use as a router gets a single (i.e., /128) address from Spectru

by KA9Q 6y ago

It is not true that an ISP cannot give each customer just a single IPv6 address. The Linux box I use as a router gets a single (i.e., /128) address from Spectrum Cable on its upstream interface, and it has to explicitly ask for a separate /64 prefix to advertise on the local interface (this is called prefix delegation, PD). So it's certainly possible for an ISP to give a customer just one IPv6 address. I'm not sure, but I think there is no rule that prefixes obtained with PD must be /64's. They could in principle give you a /126 or /127 to limit you to just a few hosts on your LAN, and charge to give you anything better. This would break stateless autoconfiguration but it would still work with DHCPv6. Your best workaround is still www.tunnelbroker.com, HE's free IPv6 tunnel service.

DaiPlusPlus 6y ago
Thank you for correcting my misunderstanding of IPv6! :)
sedachv 6y ago
> The Linux box I use as a router gets a single (i.e., /128) address from Spectrum Cable on its upstream interface, and it has to explicitly ask for a separate /64 prefix to advertise on the local interface Ask for a /56! Spectrum in Los Angeles hands out /56s, and I understand many other residential IPv6 ISPs do as well. You get your own 8 bits worth of subnets on top of /64 for easy SLAAC address assignment. This works "for free" not only because the IPv6 address space is large enough to do this, but more importantly because IPv6 does NOT have any fixed subnet sizes - routing is hierarchical and subnet assignment is transparent. /64 is just the size used by SLAAC address auto-configuration, another bit of IPv6 magic.
jlgaddis 6y ago
Phil, Thank you so very much for NOS, which was my very first introduction to IP over packet and what initially got me interested in amateur radio (going on 30 years ago!) and is, in part, what led to me initially getting licensed and drawn into the world of networking at a young age. 73, N9WWV -- P.S. Welcome to HN!

by KA9Q 6y ago

DaiPlusPlus 6y ago

Thank you for correcting my misunderstanding of IPv6! :)

sedachv 6y ago

> The Linux box I use as a router gets a single (i.e., /128) address from Spectrum Cable on its upstream interface, and it has to explicitly ask for a separate /64 prefix to advertise on the local interface Ask for a /56! Spectrum in Los Angeles hands out /56s, and I understand many other residential IPv6 ISPs do as well. You get your own 8 bits worth of subnets on top of /64 for easy SLAAC address assignment. This works "for free" not only because the IPv6 address space is large enough to do this, but more importantly because IPv6 does NOT have any fixed subnet sizes - routing is hierarchical and subnet assignment is transparent. /64 is just the size used by SLAAC address auto-configuration, another bit of IPv6 magic.

jlgaddis 6y ago

Phil, Thank you so very much for NOS, which was my very first introduction to IP over packet and what initially got me interested in amateur radio (going on 30 years ago!) and is, in part, what led to me initially getting licensed and drawn into the world of networking at a young age. 73, N9WWV -- P.S. Welcome to HN!