I did an assignment on networking last year, from what I found out it was that the service providers are having problems with traffic flows. IPv6 behaves diffe

I did an assignment on networking last year, from what I found out it was that the service providers are having problems with traffic flows. IPv6 behaves differently than IPv4 (which is known and predictable) and that the network congestion tools need to catch up. You are in effect having to monitor and adjust core routers for double the number of packet types. The network administrators are not against IPv6, it's just that it requires careful steps forward.