N reasons for not deploying ipv6 (was: Re: [narten at us.ibm.com:PI addressing in IPv6 advances in ARIN])

[Iljitsch van Beijnum]

On 18-apr-2006, at 11:29, Sam.Wilson at ed.ac.uk wrote:

> Excuse me while I delurk.

You're excused.

>> I think that's a fairy tale too. What kind of gear that you can buy
>> today can't do IPv6? And how much of that is un-upgradable? ...

> - VOIP phone systems from at least one major manufacturer, and no
> timescale for IPv6 support - big money and no idea about upgrades;

I would be surprised if those have IPv4 in ASICs.

And how many people are doing end-to-end VoIP over the internet,  
anyway? I set things up so that I can be called at my email address  
but I'm having a hell of a time finding someone who can call me to  
test this.

> - management access to network kit - we have many hundred edge  
> switches
> on our campuses

Again, how much of this has IPv4 in ASICs and is therefore  
unupgradable and also needs to communicate across the net?

> (OK we can continue to manage them on IPv4 private
> addresses like we do now, but that's not the brave new world, is it?);

:-)  Well those who've sipped the kool-aid will probably not be fazed  
by a few legacy management issues, while those who stopped reading  
RFCs in 1995 are probably not swayed by the opposite...

> - IPv6 multicast support in edge switches - we're just beginning to  
> get
> IGMPv3 support in the latest products and there's enough IGMPv2  
> support
> out there that we can envisage turning on IPv4 multicast most places
> anyone needs it, though there are still significant islands of kit  
> that
> don't support it at all (switches running software whose release notes
> are dated 1997, for instance).  It will be ~5-10 years before we could
> think of having that stuff replaced with kit that's contemporary now.

Are there any switches that support MLD snooping, by the way? (Not  
even talking about MLDv2...) I haven't heard of this. Unfortunately,  
there are multilayer switches that implement IGMPv2 and assume  
multicast for which they don't see IGMP must be blocked, which is of  
course nonsense because you can't send IGMP messages for non-IPv4  
ethernet group addresses.