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Comment Re:IPv6 isn't the solution (Score 1) 327

Let's see: one person points (very accurately) one of the main reasons why IPv6 isn't widely deployed at the moment: lack of any kind of backward compatibility with IPv4. He gets modded "0, redundant". Another person mentions 6to4, and gets modded "5, insightful". Looks like the mods have been listening to way too much IPv6 marketing, and are starting to believe it.

Look a little more into the subject, and you will see that 6to4 does not offer backward compatibility in any way, shape or form. It is simply a way for IPv6 "islands" to communicate over an IPv4 network.

The real problem, however, is getting an IPv6-only host to communicate with an IPv4-only host. Until we have that, there is no backward compatibility to speak of. And so far, the only mechanism that can do that (at least partly) is a form of NAT - NAT64. And that is still in its infancy, works only one way (v6 client to v4 server), and brings with it all the disadvantages of NAT (which we are trying so hard to avoid by moving to IPv6).

Even though I do not agree with his solution to the problem (I don't think his multicast solution would have solved the problem), the OP (Alomex) is right - there is no backward compatibility built into IPv6. And this is what has hindered IPv6 adoption from the very beginning.

Comment Why isn't IPv6 deployed? Let's see... (Score 2) 327

I'm surprised nobody has posted this yet:

http://meetings.ripe.net/ripe-55/presentations/bush-ipv6-transition.pdf

It's a presentation I keep coming back to again and again (every single time somebody asks me "why don't people deploy more IPv6?").

Yes, the font and colors used will make your eyes water (I really wonder if he actually chose them that way on purpose :) ). But the actual content is just as accurate now as it was in 2007, and it comes from someone who actually has quite a bit of experience working with this stuff...

Comment Re:Unlikely (Score 2) 177

By your standards, bread is the same density as dough, and swiss cheese the same density as... regular cheese :) Face it - sometimes the holes in the structure of the material are relevant, and will affect the overall density (and the fact that they are uniformly distributed is relevant, which excludes your tent). Even ice has a lower density than water because of "tiny holes" in its structures (actually, these "holes" are increased spaces between the atoms making up the ice).

Comment Re:An unfair comparison (Score 1) 406

Absolutely. The air is just one big tube.

However, I wonder if it would be faster to just dump a bunch of carrier pigeons on a truck instead and transfer the data that way?

As opposed to just dumping the memory cards in the truck? (which somehow seems... simpler :) )

"Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway." - Tanenbaum, Andrew S. (1996)

Comment Re:Net neutrality anyone? (Score 1) 122

CEF (Cisco Express Forwarding) and MPLS [wikipedia.org] (Multiprotocol Label Switching) use flow control. The perform a lookup on the first packet, cache the information in a forwarding table and all further packets which are part of the same flow are switched, not routed, at effectively wire speeds.

It's more than that. The older techologies ("fast switching" in the Cisco world) used to do this - route first packet, then switch the other packets in the flow. However, CEF goes one step forward, and allows for all the packets to be switched by the hardware (not even the first packet in the flow hits the router processor). Which means that what the author seems to be suggesting would actually mean moving backwards.
Either there is more to the router than the article says, or the author hasn't been keeping track of developments in this field...

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