In addition, IPv6 has link local addresses. This one seemingly insignificant detail causes so much code churn and is probably responsible for 10 years of the IPv6 drag.
AFAICT, Cisco V6 HSRP (mentioning that brand only because it caused me to try to figure something out, a coincidence that this is in reply to Jakob from Cisco but is based on what he wrote) relies on Link Local addresses. I didn't understand why link locals should be there in the first place seemed klugey and have googled, looked at rfcs and tried to understand why link local addresses were baked into V6. The only thing I found was that it enabled interfaces on point to point links to be unaddressed in V6. (To save address space!??) Can anyone point me in a direction to understand the reasoning for link local addressing? dennis