Change DHCP-Server Address

Bernd Nachtigall bnacht at
Mon Jun 28 13:24:20 UTC 2021

With the recommended option in dhcpd.conf it is running perfect :-)

But maybe they may clean up the documentation:

server-identifier hostname;

... The value specified must be an IP address  for  the
DHCP server, ...

Maybe is is more clear to write:

server-identifier IP-Address;

... The value specified must be an IP address  for  the
DHCP server, ...



Am 28.06.21 um 08:50 schrieb glenn.satchell at
> On 2021-06-28 16:31, Bernd Nachtigall wrote:
>> Hi,
>> there is a DHCP-Service which is configured to use a secondary
>> IP-Address. This runs fine.
>> Main IP: Sec. IP:
>> But when check the answers from the service at a client it seems
>> that the service use the main IP as sender. Is there a way to
>> configure the dhcpd that it uses the sec. IP-Addr. as 'from' when
>> answering to clients?
>> Bernd
> Hi Bernd
> Looks like you need to use the server-identifier statement. This is
> from the dhcpd.conf man page:
> The server-identifier statement
> server-identifier hostname;
> The server-identifier statement can be used to define the value that
> is sent in the DHCP Server Identifier option for a given scope.  The
> value specified must be an IP address  for  the  DHCP server, and
> must be reachable by all clients served by a particular scope.
> The  use  of  the  server-identifier  statement is not recommended -
> the only reason to use it is to force a value other than the default
> value to be sent on occasions where the default value would be
> incorrect.  The default value is the first IP address associated with
> the physical network interface on which the request arrived.
> The usual case where the server-identifier statement needs to be sent
> is when a physical interface has more than one IP address, and the
> one being sent by default isn't appropriate  for  some or  all
> clients served  by that interface.  Another common case is when an
> alias is defined for the purpose of having a consistent IP address
> for the DHCP server, and it is desired that the clients use this IP
> address when contacting the server.
> Supplying a value for the dhcp-server-identifier option is equivalent
> to using the server-identifier statement.
> regards, Glenn
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