Does anyone use anycast DHCP service?

Victor Kuarsingh victor.kuarsingh at
Mon Aug 13 17:18:27 UTC 2012

Sent from my iPad

On 2012-08-13, at 12:18 PM, sthaug at wrote:

>> I think it would be far more reliable to simply have two independent
>> DHCP servers with mutually exclusive address ranges, and have one
>> system be secondary and "delay" its responses by 2s so it always
>> "loses" when the primary is up and running well.
>> Yes, you lose the ability for clients to get the same IP during a
>> lease refresh if the primary is down, but that is a small price to pay
>> for simplicity and robustness.
> That depends on your scenario. In some situations it is important to
> get the same IP. In other situations, using potentially double the
> address space is unacceptable.

As some have noted, your environment may dictate which is better (HA with software considerations, or retention of IP lease information).


In an ISP environment, I would suggest that you consider prefix delegation for IPv6 (--assuming you plan on IPv6 at some point ).

For traditional IPv4 networks (ISP), changing the WAN side IP address occurs often enough that it's annoying, but tolerable.  When we consider IPv6, changing the WAN side IP is also reasonable (IA_NA).  But if you plan on supplying the home network a prefix delegation (IA_PD), you get into some problems if you wind up renumbering the home network.

Not sure if this example fits your profile, but at this point, I would not consider a deployment of any major system without considerations of IPv6.


Victor Kuarsingh


More information about the NANOG mailing list