ipv6 anycast: any practical usage example?

johnifanx98

I knew it's "one-to-nearest". But to be honest, I'm little bit lost when we will need this function. Does it have any peer function in IPv4?

Ltat42a

DHCP comes to mind. A new PC placed on a network is looking for a DHCP server to request an IP stack.

johnifanx98

Cool! This is a great example where anycast beats the broadcast.

Thanks,

networker050184

The same thing can be used in IPv4, just assign the same IP in multiple places and let traffic route to the nearest one. I've seen this used for BGP next hops, DNS etc.

xXErebuS

Akamai services come to mind....

m3zilla

Ltat42a wrote: »

DHCP comes to mind. A new PC placed on a network is looking for a DHCP server to request an IP stack.

I'll be honest...I have no clue how DHCP works in IPv6, but in IPv4, a PC broadcast for a DHCP, it doesn't send a unicast. I assume in IPv6, it's going to send some sort of multicast, and not unicast, so I don't see how an anycast would work for DHCP.

Trifidw

DHCP requests are multicast on ff02::1:2. A better example of anycast would be to replace a FHRP such as HSRP or GLBP. I expect servers will be using this feature too to load balance.

xXErebuS

I've thought about this and I'm not sure about that one; going to the closest one isn't exactly load balancing... there would have to be some work done.