[AusNOG] FW: [Ap-ipv6tf] official shutdown date for IPv4. The date he is pushing for is April 4, 2024. "IPv4 can't go on forever, " Latour said. "

[Jeremy Visser]

On 06/11/14 12:43, Jonathan Thorpe wrote:
> In practice, devices that can manage failover for small sites over a 
> couple of business grade DSL Services from diverse providers have a 
> low barrier of entry (achievable for around $100 and easy to set up) 
> and can in some cases be scaled to support device level redundancy 
> (pfSync etc).
> 
> In IPv6, the premise that sites should advertise address space 
> upstream to achieve this makes it all but impossible because: * Sites
> need to now get an ASN, pay for and manage their own public address 
> space.

I think you misread Mike in the above.  Nothing he suggested implied that getting advertising a prefix assignment upstream or getting an ASN.

What he was suggesting was running two routers in parallel (or one router with two upstreams) and advertising separate prefixes (i.e. dual Router Advertisements) which causes each device to get two sets of global addresses.

These routers don't even need to be aware of each other.  They should just sit on the same Layer 2 broadcast domain firing off Router Advertisement packets.

As Mike said:

> IPv6 based failover you simply advertise both prefixes and the client
> can chose which source address to use
> 
> For IPv6 you simply have both routers plugged in at the same time,
> if one goes down it stops advertising itself and clients stop using
> it.

When one router's WAN goes down, it will send out an RA packet notifying that the prefix is deprecated, and clients will stop using those addresses.

Obviously a larger institution will want to get their own /48 allocation and an ASN, but it is possible to do it on the cheap too.