What happens to clients that sends a DHCPDECLINE

[Yi Chen]

Hi,

I wonder if anyone can help me clarify something I read in RFC 2131. According to the RFC:

4.3.3 DHCPDECLINE message

If the server receives a DHCPDECLINE message, the client has
discovered through some other means that the suggested network
address is already in use. The server MUST mark the network address
as not available and SHOULD notify the local system administrator of
a possible configuration problem.

However, what the RFC doesn't seem to cover is what happen if the IP being DECLINEd is a static DHCP host. Should the DHCP server keep ignoring the client or give it a dynamic IP from an appropriate range? Since the purpose of a static DHCP host is to make sure that client always gets the same IP, I would think that ignoring the client would be the right approach.But I thought I should ask the people on this list who are much more experienced with DHCP than I do :)

Thanks in advance,

Yi Chen

[Ted Lemon]

Post by Yi Chen
However, what the RFC doesn't seem to cover is what happen if the IP
being DECLINEd is a static DHCP host. Should the DHCP server keep
ignoring the client or give it a dynamic IP from an appropriate
range? Since the purpose of a static DHCP host is to make sure that
client always gets the same IP, I would think that ignoring the
client would be the right approach.But I thought I should ask the
people on this list who are much more experienced with DHCP than I
do :)

DHCPDECLINE is used by the client to indicate that the IP address that
was leased is in use by some other device. So ignoring a DHCPDECLINE
is a bad idea. What you should do instead is to notify the
administrator with some urgency that the IP address is in use.
Whether to offer the client another IP address, or to ignore it until
such time as the problem is corrected, is probably something that
should be configurable by the operator.