There have been claims of tools used for scanning IPv6 networks both from security companies and from crackers.  So, finding networks might not be as big a problem as know what you found and where you are and how it relates to your target. 

I think the issue of hiding networks will require a number of NAT like systems or network segments based on the type of resource that you are attempting to protect.  It could require increased monitoring points along with the usual IDS, Firewalls and AV. Everyone seeing everything might be a bit of a problem.   

Teedge77,

Excellent question.  This is my first reply and I am a new member so, I hope that my disagreeing with some of the other replies will not offend anyone.  You are correct IPv6 is here. The Federal Government has been mandated by the Office of Budget and Management to migrate to IPv6 by June 30th 2008.  Typically many government agencies won’t make the three year old deadline but, the change has begun. 

Now, to your question. It is a question that I am researching myself.  What network tools work and which don’t?  What are the security implications for applications like VoIP?

It depends on the tool and vendor.  Some of the major vendors have had dual stack products for a while.  Other vendor tools and tools with lower levels of support may not be ready.  Equipment will also be a factor.  Services like FTP, at last I knew are not supported in IPv6 on Cisco routers. 

There are already a number of hacks advertised for IPv6.  I don’t know how well they work or on what types of equipment but we will start to see soon. 

The bottom line is for every tool that we use we are going to have to contact the vendor, do some research or test.  My hope is that as we identify tools that work and tools that do not we share the information to save the next person some unnecessary headaches.