host statement scope rules (ISC DHCP 3.0.5b1)
sten at s-carlsen.dk
Tue Aug 1 16:20:09 UTC 2006
While nobody WANTS to mess things up like here, it could happen by
mistake. E.g. I start with one subnet and for readability puts my host
statements here. Then I expand with another subnet and a different set
of host statements. At some stage one of these hosts or by repair only
the netcard moves to the other subnet. Things have stopped working and I
have done nothing. This needs a heavy warning, that possibly could be
disabled if you really know what you are doing; but then your repairman
may not know that.
Bruce Hudson wrote:
>> Is there any real reason to need the inheritance of putting a host
>> declaration within a subnet ? I guess it comes down to, will the host
>> inherit anything that it wouldn't have inherited anyway by virtue of
>> being 'put there' as the server allocates it to a subnet for lease
>> allocation purposes ?
> If I recall complaints from a while ago correctly, the answer has
> been known to be yes. There was list traffic discussing a host declared
> within a subnet, using a dynamic address on another subnet, that was
> incorrectly inheriting and using parameters from the first subnet. I
> cannot think of any setup where somebody would want to do this: give
> parameters to any host using a network adddress AND any of a set of
> hosts no matter where they are used. I suppose it is possible somebody
> might want to do it on purpose in the name of "efficiency" -- to avoid
> duplicating a few statements in an explicit block.
> Unfortunately I cannot find the messages I am thinking of and I do
> not recall whether the syntactic declarations were over-riding those
> provided by the subnet used or just providing parameters that were not
> supposed to be configured at all in that context.
> Bruce A. Hudson | Bruce.Hudson at Dal.CA
> UCIS, Networks and Systems |
> Dalhousie University |
> Halifax, Nova Scotia, Canada | (902) 494-3405
No improvements come from shouting:
"MALE BOVINE MANURE!!!"
More information about the dhcp-users