how respond only to specific clients

[Simon Hobson]

Carl Karsten wrote:

>  > All your hosts you want to supply dhcp to will need to be defined in a
>>  host statement. You'll need one of these for each known host.
>>
>>  Something like this should do it:
>>
>>  host foo1 { hardware ethernet aa.bb.cc.dd.ee.ff; }
>>  host foo2 { .... }
>>  ...
>>
>>  subnet 192.168.0.1 netmask 255.255.255.0 {
>>    pool {
>>      option routers 192.168.0.1;
>>      option ...
>>      ignore unknown-clients;
>>      range 192.168.0.10 192.168.0.254;
>>    }
>>  }
>>
>>  Repeat for as many hosts and subnets as required.

>Don't you need that whole thing wrapped in a group { .. } ?

No. That is optional, and would typically be used when you want to 
add/change some option(s) for a bunch of hosts - perhaps you want to 
give 'known' hosts a longer lease time. Instead of adding options to 
each host statement, you put them in a group and add the options to 
the group.

>Also, what is going to make it " look for another dhcp server." ?

The client will broadcast for a server to give it an offer. If 
there's more than one server then they should all reply (if 
configured). If this server is configured not to answer, and another 
one does, then the client will automatically use the offer it gets 
from the other server.

So really there is no such thing as 'looking for another server', it 
all comes under looking for any and all servers that service the 
subnet.

>I don't think what is being requested can be done, at least not reliably.  the
>"look for another dhcp server" sounds like "broad cast again and see if the
>other server responds quicker this time" and there isnt anything 
>preventing that
>from happening the first time.

It does work, as described above. No special settings other than 
configuring which servers will consider/ignore which clients.

Simon