[mdlug] OT: the great IPv6 debate

[Aaron Kulkis]

Dan Pritts wrote:
> On Thu, Apr 22, 2010 at 03:28:35PM -0400, Adam Tauno Williams wrote:
>> Nah, working multicast and mobile IP support are a big deal.
> 
> IPv4 SSM works more or less as well as IPv6 multicast does.
> 
> Mobile IP support, yeah, that's cool.
> 
>> And I hardly call the radical reduction of CPU resources to perform
>> routing to be 'gravy' for backbone routers.  Think about it: IPv4
>> requires a CRC check at each hop,  do that on every packet in a ^&*^&*@
>> YouTube video stream for every &^&*# YouTube user at every hop and that
>> adds up to a lot of processing, ASIC or no ASIC.  Just dispensing with
>> that is a big deal.
> 
> somehow, all the packets get moved.  It's a lot less effort to do this in
> the network than it is to change absolutely everything 

Only for the first packet delivered by IPv6 via that node
(topologically) within your network.
After this one-time cost is paid, the benefits of lower costs
accrue both immediately, and forever.


> 
> 
>>> Probably the biggest problem is that application software often
>>> does not handle things gracefully when a supposedly dual-connected
>>> site is v4-reachable but not v6-reachable.
>>> Try an experiment; put a bad AAAA record in your DNS for a test web
>>> server, try to connect using a browser on a v6-configured host.
>>> (put in a good A record, too).
>> Eh.  Seriously, that is your complaint?  Fix your DNS.  I don't expect a
>> client application to compensate for incorrect information.
> 
> My complaint isn't what happens when DNS is broken.  My problem is 
> what happens when:
> 
>   My system has a v6 and v4 address
>   The server has a AAAA record and an A record.  
>   I have v4 reachability but not v6 reachability to the server
> 
> This happens pretty frequently in my experience.

Why does your DNS server frequently have incorrect records?

> 
> Obviously this is a transitional problem - but it's a big one.

More than anything, it sounds like incompetent and/or improper
administration somewhere.

>