Re: limit dhclient to one server only?

[Jukka Marin <jmarin%embedtronics.fi@localhost>]

On Fri, Aug 16, 2013 at 08:52:49AM +0100, Patrick Welche wrote:
> On Fri, Aug 16, 2013 at 10:41:43AM +0300, Jukka Marin wrote:
> > On Fri, Aug 16, 2013 at 08:38:38AM +0100, Patrick Welche wrote:
> > > > > I haven't tried it, but in dhcpcd.conf(5), this looks promising:
> > > > > 
> > > > >      whitelist address[/cidr]
> > > > >              Only accept packets from address[/cidr].  blacklist is 
> > > > > ignored if
> > > > >              whitelist is set.
> > > > 
> > > > Thanks, but in this case the clients don't know the server's address :(
> > > 
> > > So how is it a "known DHCP server"? IPSEC on bootps/bootpc ports?
> > 
> > It should supply a special option value or something like that to the 
> > clients,
> > allowing the clients to recognize it as "our server".
> 
> Something like a "vendor encapsulated option"?

Probably, but can you make dhclient require a certain option _and_ a certain
value for the option (not just that the option exists - the option numbers
may be used by some other dhcp server which would break the system unless a
special unique value was also required).

  -jm