Interference between multiple DHCP instances on the same server

Glenn Satchell glenn.satchell at
Thu Apr 29 04:47:21 UTC 2010

If the two interfaces are on the same subnet it shouldn't matter which 
interface they send their responses out. This is a function of the 
kernel's network stack and is outside the control of dhcpd.

Use of server-identifier should tell the clients to send their response 
back to that particular server ip, rather than the source IP of the 
packet. I would assume that you have different IPs on the two interfaces.

Apart from observing the traffic, are there any errors reported, or 
dhcpd not functioning correctly?


On 04/28/10 20:55, Abu Abdulla alhanbali wrote:
> Hi,
> I have installed additional DHCP instance on the same physical machine
> (different interface) that has another DHCP.
> I’m binding each server with the interface at the startup: dhcpd
> <options>  <interface>
> On the other hand, I’m noticing strange behavior:
> The second server is receiving the request from the correct interface
> but the response is sent from the other interface. I checked this by
> ‘snoop’ the two interfaces. I tried also compiling the server
> (solaris) with USE_SOCKETS support (even though it is designed for
> another purpose) and define local-address / server-identifier without
> success.
> Any hint where could be the problem.

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