HA options

[墨泪]

I have the nearly the same problem. I need DHCP HA, but not DHCP load balancing. here is my situation:

1. I have a 8C network split to two 4C’s subnet
2. Both subnet set the `ip helper address` to one IP(suppose 192.168.2.1 here) on the switcher
3. DHCP servers (suppose two DHCP server) runing in the first 4C’s subnet (so DHCP server can receive all DHCPDISCOVER request in the first 4C’s subnet, but only the server who has ip 192.168.2.1 can receive DISCOVER request in the second subnet)
4. use DHCP failover protocol to keep dhcpd.leases db file in sync
5. use `Keepalived` to KEEP VIP 192.168.2.1 for routing

Then the bad things happen. Every thing works fine in the first 4C, because each server received all DISCOVER request, and response in order. But requests from the second 4C have some trouble in server response:

1. suppose I have two dhcp server names `A` and `B`
2. `A` is the main server, and it hold the ip 192.168.2.1 by default.
3. DHCP pool split by 128 (half half)
4. `A` server receive request `a` and response fine.
5. `A` server receive request `b` and it think `B` server should response for this request, then `A` omitted this request.
6. Unfortunately Server `B` doesn’t receive this request (because of ip helper address settings and the Keepalived settings)
7. Pool little `b` request again and again, but nobody response

So how can I fix this problem?


On Jan 23, 2014, at 12:10 AM, Leigh Porter <leigh.porter at ukbroadband.com> wrote:

> I just use VMware HA to magically move the whole DHCP server to another bit of tin in the event of a failure.
>  
> --
> Leigh
>  
>  
> From: dhcp-users-bounces+leigh.porter=ukbroadband.com at lists.isc.org [mailto:dhcp-users-bounces+leigh.porter=ukbroadband.com at lists.isc.org] On Behalf Of Raymond Drew Walker
> Sent: 22 January 2014 16:07
> To: Users of ISC DHCP
> Subject: HA options
>  
> I’m currently researching options for DHCP high availability in our environment.
>  
> Our current setup is a dhcpd failover pair managing all networks.
>  
> Are there current options for or future plans to allow more than 2 nodes in a failover setup?
>  
> Aside from splitting up networks between multiple managing DHCP servers are there any other/better options for HA in dhcpd?
>  
> —
> Raymond Walker
> Software Systems Engineer StSp.
> ITS - Northern Arizona University
> 
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please visit http://www.symanteccloud.com
> ______________________________________________________________________
> 
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please visit http://www.symanteccloud.com
> ______________________________________________________________________
> _______________________________________________
> dhcp-users mailing list
> dhcp-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/dhcp-users

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/dhcp-users/attachments/20140123/0b602807/attachment.html>