request for advice / building dhcpd infraestructure

[Peter Rathlev]

On Tue, 2015-06-23 at 15:08 -0300, Leandro wrote:
> After I run out of those ips, I can do two thinks:
> a)change the network mask from /24 to /23.
> b)Add a second /24 subnet behind the relay , for example 1.1.2.0/24 and 
> set a second gateway ip 1.1.2.1/24.
> 
> option a) is not good since the broadcast domain at /23 could bring many 
> collisions. (its just my opinion).

For a regular Ethernet switched network, /23 doesn't sound like a lot.
At modern speeds and with modern operating systems the baseline
broadcast should be negligible.

> option b) Could work but, how does relay agent knows witch ip to use for 
> GI-Adrr ?
> Can relay agent send both or more than one ips, on the GI-Addr field so 
> dhcpd can figure out from witch range can serve the ip ?

You would use "shared-network" for this. The GI-Addr just has to fall
within one of the subnets inside the shared-network statement. The DHCP
server will then hand out an address from a random subnet. Take a look
at the dhcpd.conf man page for the syntax.

-- 
Peter