[NTLUG:Discuss] DHCP

[Johnny Cybermyth]

It is very true regardless of OS.  A DHCP server is only aware of IP 
through its self maintained "leases" file.  If an address is not present 
in the leases file, then it is assumed to be available for use.

You should always assign blocks of DHCP only address and then use static 
addresses outside of those blocks.

I've not heard of a DHCP server that detects this condition and works 
around it automatically.

Terry wrote:
> Is this an accurate statement (pertaining to a Linux DHCP server
> presiding over [mostly] MS PCs)?
>  
> "Having a system with a static IP assignment that is inside the range
> of IPaddress' used by a DHC P server is not acceptable.  Reason being:
>  If a new computer comes on-line, it may be issued that particular
> IPaddress, and if so, there will be a problem.  This may never happen
> on a small network. If there are only a handful of computers on the
> network (half a dozen or so), you may never run into this sort of
> problem.  BUT, if and when the network grows and gets to be fifty or a
>  hundred strong, sooner or later, this problem will rear it's ugly
> head.  A computer will come on-line and be issued an IP address that
> has been set as a static address to another computer, .. . and then,
> later on, that other computer with the static IP address will come
> on-line, and at that point they will both compete for access that only
> one can have. During the competition neither of them will get any
> access and only when one gives up will the other gain any bandwidth or
> access to any outside networks. Fixed IPs should _only_ be assigned to
> IP address that are outside the range used by the DHCP server."
> 
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