Subject: Multiple IP address allocations

From: "William Parton" <[email-masked]>
Date: Thu, 15 Mar 2001 11:36:04 -0000

I am looking at an application that requires multiple IP addresses to be
allocated to a single device. There is an additional complication that there
is a relationship between the multiple addresses (in this case four
contiguous IP addresses must be allocated to a single device).

I see from the DHCP FAQ that a typical DHCP server implementation should:
"Allow manual allocation of two or more alternative IP numbers to a single
MAC address, whose use depends upon the gateway address through which the
request is relayed." This appears to be along the lines of what I'm looking
for (except that all four requests would come via the same gateway address)
and hints that multiple address allocation for a single device may have been
addressed in this forum. 

There would seem to be two ways of achieving multiple IP address
allocations: 
- multiple DHCPDISCOVER requests, with the DHCP server being configured to
allocate IP addresses to the device taking into account any relationships
between the IP addresses. This may mandate the use of static IP address
allocation.
- or a single DHCPDISCOVER/DHCPOFFER pair, but have multiple IP addresses
allocated within the DHCPOFFER (using a suitable vendor extension).  

The first option would appear to be more in keeping with the DHCP
architecture but requires additional controls and management within the DHCP
server.

Has such an requirement been previously addressed? I have not been able to
find any relevant information in the FAQ or DHCP-v4 archives.

regards

Will