On Jun 8, 2011, at 7:24 PM, William Herrin wrote:
On Wed, Jun 8, 2011 at 9:58 PM, Kelly Setzer <Kelly.Setzer@wnco.com> wrote:
IPv6 newbie alert!
I thought the maximum prefix length for IPv6 was 64 bits, so the comment about a v6 /112 for peering vexed me. I have Googled so much that Larry Page called me and asked me to stop.
Can someone please point me to a resource that explains how IPv6 subnets larger than 64 bits function and how they would typically be used?
Hi Kelly,
IPv6 netmasks work exactly like IPv4 netmasks. You can even route /128's if you want. Two major caveats:
1. SLAAC (stateless autoconfiguration, the more or less replacement for DHCP) only works if the subnet on your LAN is exactly /64. So unless you're manually configuring the IPv6 address on every machine on your subnet, you're using a /64.
You can actually use DHCPv6 to assign addresses to hosts dynamically on longer than /64 networks. However, you may have to go to some effort to add DHCPv6 support to those hosts first. Owen