The main reason I haven't switched my networks to IPv6 is that I plainly don't want to support both protocols at the same time. If I could just switch over to IPv6 and leave v4 behind I would, but I just can't be bothered to do twice the work every time I setup a firewall or a router. Double the config, double the tests and on top of that you have to make sure everything inter-operates smoothly when IPv4 alone still just works.
As you mention in your other post it really is the "billion dollar mistake", it's obvious to me in hindsight that they should have made IPv6 completely backwards compatible with IPv4, no matter the cost. Have a deprecation procedure later on if you want to remove the hacks necessary to support IPv4. Have a clear and simple upgrade path, one step at a time.
Sure, having a clean new standard is compelling but clearly it's making things way more difficult that they ought to be. And that's how we end up more than 20 years after RFC1883 was released with "barely" 20% adoption. NATing was easier than IPv6, so people NAT'ed everything and the internet became the net.
> As you mention in your other post it really is the "billion dollar mistake", it's obvious to me in hindsight that they should have made IPv6 completely backwards compatible with IPv4, no matter the cost.
It's not a matter of cost, it's simply impossible.
IPv4 has a 32 bit field for the source address and a 32 bit field for the destination address, and every connection over IP needs to send packets back and forth between the two addresses. As soon as one party has a longer address, the other party has to know how to handle that, otherwise, they cannot possibly communicate.
The only point where compatibility would be possible to some degree is the network, but (a) that compatibility is in effect a tunnel, and there are lots of ways to tunnel IPv6 over IPv4 just fine, and (b) most of the global internet supports IPv6 just fine, and has been for a long time. The problem is the migration of the endpoints, not so much the network.
It sucks at being compatible with ipv4. The "billion dollar mistake" :-)
It also sucks at having software/hardware stacks nearly as well debugged as those for ipv4, which means running ipv6 at all is a security risk.
Nobody would switch for sundry technical advantages. The main driver for conversion is that ipv4 addresses are scarce. As soon as "we" seriously "move to ipv6", however, the scarcity driven pressure to convert is relieved. We're bound to reach an equilibrium that will include ipv4 for a long time, possibly forever.
simias|8 years ago
As you mention in your other post it really is the "billion dollar mistake", it's obvious to me in hindsight that they should have made IPv6 completely backwards compatible with IPv4, no matter the cost. Have a deprecation procedure later on if you want to remove the hacks necessary to support IPv4. Have a clear and simple upgrade path, one step at a time.
Sure, having a clean new standard is compelling but clearly it's making things way more difficult that they ought to be. And that's how we end up more than 20 years after RFC1883 was released with "barely" 20% adoption. NATing was easier than IPv6, so people NAT'ed everything and the internet became the net.
zAy0LfpBZLC8mAC|8 years ago
It's not a matter of cost, it's simply impossible.
IPv4 has a 32 bit field for the source address and a 32 bit field for the destination address, and every connection over IP needs to send packets back and forth between the two addresses. As soon as one party has a longer address, the other party has to know how to handle that, otherwise, they cannot possibly communicate.
The only point where compatibility would be possible to some degree is the network, but (a) that compatibility is in effect a tunnel, and there are lots of ways to tunnel IPv6 over IPv4 just fine, and (b) most of the global internet supports IPv6 just fine, and has been for a long time. The problem is the migration of the endpoints, not so much the network.
libeclipse|8 years ago
Why? ipv6 is so much better than ipv4 it's insane that we're even discussing this.
cronjobber|8 years ago
It also sucks at having software/hardware stacks nearly as well debugged as those for ipv4, which means running ipv6 at all is a security risk.
Nobody would switch for sundry technical advantages. The main driver for conversion is that ipv4 addresses are scarce. As soon as "we" seriously "move to ipv6", however, the scarcity driven pressure to convert is relieved. We're bound to reach an equilibrium that will include ipv4 for a long time, possibly forever.