> "Ethernet doesn't scale because of large amounts of broadcast traffic." > > We started to introduce multicast, and multicast-aware switches in > IPv4; in IPv6 there is no broadcast traffic. We won't be able to > scale networks up until we can turn off IPv4,
In other words, probably not for another decade at least? > but once we can IPv6 > will be able to grow much larger in terms of per-LAN. The best > practice of no more than 512 per broadcast domain will seem very > outdated at that point; especially when you add in multicast flood > protection, the available bandwidth goes up, and performance of > network interfaces improves. Yes and no. If you remove the broadcast traffic you can *in theory* scale higher. However, this does nothing for the difficulty of L2 troubleshooting, which is a real problem in large flat L2 networks. > The link you pointed to is talking about flat networks of tens of > thousands of hosts; that might be excessive right now... But I can > certainly see an IPv6-only LAN (with some filtering to make sure ARP > and IPv4 traffic is dropped at the port) scaling easily to thousands > of hosts with today's hardware. I'm afraid I remain sceptical, unless we come up with significantly improved methods for L2 troubleshooting. Steinar Haug, Nethelp consulting, [email protected]
