Re: Rethinking autoconfig, was Re: prefix length determination for DHCPv6

[Iljitsch van Beijnum <iljitsch@muada.com>]

On 17-sep-2007, at 14:03, Mark Smith wrote:

> What is the motive for reducing the number of packets, and  
> multicast in
> particular?

Packets use up bandwidth and other resources. The main issue with  
multicast is with wifi and similar networks. Unicast packets are  
acknowledged on those networks and retransmitted at lower speed if  
necessary. With multicast this isn't possible, so those are always  
sent at a low speed and never retransmitted. So they use up more link  
capacity but are less reliable.

In a network such as an IETF meeting network, one or two extra  
multicast packets in the autoconfiguration process can lead to enough  
extra traffic to noticeably impact performance. (Although multicast  
DNS traffic is probably much worse than autoconfig traffic with  
current implementations.)