ipv6 DHCP server as anycast

[avanth chidurala]

Hi we are about to implement ipv6 in our network, Instead of configuring DHCP server can we configure anycast server for IPV6 address 

[Flavio Miranda]

Hi @avanth chidurala

 Looks like you want to replace DHCP by anycast but I understand that anycast has a different function. Anycast is something like Multicast in IPv4. 

"Anycast addresses can be used only by a device, not a host, and anycast addresses must not be used as the source address of an IPv6 packet."

-If I helped you somehow, please, rate it as useful.-

[James Leinweber]

No, addresses in IP networks can be unicast (single source or destination), anycast (multiple possible destinations, routers pick just one "nearest"), multicast (multiple simultaneous destinations), or in IPv4 broadcast (all link-local destinations).  Sources are almost always unicast; destinations can be any type. 

Anycast addresses are used to minimize latency, reduce backbone traffic, and increase resiliency by distributing traffic across multiple servers.  The most common use of anycast destinations isfor DNS redundancy.  The obsolete IPv6 6to4 relays were also anycast.  E.g. there are only 13 root DNS server addresses, but there are around 500 actual servers sharing those addresses.

DHCPv6 is aimed a  different issue: how addresses get assigned to host interfaces.  Alternatives to DHCPv6 are static (manual intervention by host administrator) and SLAAC (stateless configuration where the router advertisement specifies prefixes and the host self-generates the bottom 64 bits).

-- Jim Leinweber, WI State Lab of Hygiene