DHCPNAK reply using wrong server identifier IP

[Glenn Satchell]

dhcp-server-identifier sets the IP inside the internal dhcp option space,
not the source IP address on the packet.

regards,
-glenn

> Hi ISC-DHCP-Users,
>
>
>
> I have configured dhcpd.conf to use an global 'option
> dhcp-server-identifier
> xxx.xxx.xxx.xxx' directive since my server box has more than one IP
> (raised
> on an alias device). This 'dhcp-server-identifier IP' is actually an alias
> IP via eth0:0.
>
> Now, after playing with Wire Shark, I noticed that each time the server
> issues a DHCPNAK reply (due to a client DHCPREQUEST for a wrong IP), the
> DHCPNAK is being sent thru the real IP in eth0, and not thru the
> configured
> 'option dhcp-server-identifier IP' eth0:0 IP.
>
> My questions now are:
>
> 1. Is there a specific reason why DHCPNAK replies do not follow the global
> 'option dhcp-server-identifier xxx.xxx.xxx.xxx' directive?
> 2. Should I use a 'server-identifier IP' sub-directive ('tho I haven't
> tried
> yet) instead of a global one?
>
> Any tips/explanations are very much welcome.
>
>
> Best regards,
> Vic
>