Failure of dhcp server failover

[Niall O'Reilly]

On 30 Apr 2016, at 22:41, Eugene Grosbein wrote:

> Hi!
>
> Is it possibly to run pair of ISC DHCP Servers in a failover mode
> and reliably supply static allocations for some DHCP clients,
> e.g. using pools containing single IPv4 address?

   Yes, but I wouldn’t configure for the statically-addressed devices
   using the class/fool/failover technique.  Instead, I would use
   simple host declarations, duplicated in each server’s 
configuration.

   So, instead of

>   # vlan 1600 = 0x640
>   class "ward2-vlan1600" {
>     match if binary-to-ascii(16, 8, ":", hardware) = 
> "1:44:d9:e7:58:fd:e1"
>     and substring(binary-to-ascii(16, 8, ".", option 
> agent.circuit-id), 0, 8) = "0.4.6.40";
>   }

   I would use

     host ward2-vlan1600 {
       fixed-address 10.19.50.13;
       hardware ethernet 44:d9:e7:58:fd:e1;
     }

   I expect that using agent.circuit-id is redundant, as the MAC address 
should
   uniquely identify each device.  If you need to defend against 
hardware address
   collisions, you have “other problems”.

   I hope this helps.

   Best regards,
   Niall O’Reilly