classing gateway

[Simon Hobson]

marco perugini wrote:

>i've my pool [10.0.0.0/24] and there are two different gw that forward
>dhcpdiscover to my server:
>DHCPDISCOVER from XX:XX:XX:XX:XX:XX: via 192.168.2.101
>DHCPDISCOVER from XX:XX:XX:XX:XX:XY: via 192.168.98.201
>so i want to split my pool to assign range 10.0.0.1 - 10.0.0.127 to
>192.168.2.101's requests and the other half to 192.168.98.201's; how can
>i class the gateways in dhcpd.conf? does anyone know what i have to match?

What are you trying to achieve ? What is your network topology ?

Neither of those IPs is a valid address in the 10.0.0.0/24 subnet, so 
nethier is actually valid as a gateway in 10.0.0.0/14, 10.0.0.0/25, 
or 10.0.0.128/25.

But if you mean you have two gateways, each of which serves a 
separate network, and :

192.168.2.w/x is to be a shared network with 10.0.0.0/25
and
192.168.98.y/z is to be a shared network with 10.0.0.128/25

then all you need to do is declare the shared networks properly and 
the rest is automagic.

So why the shared networks ?


Just to be sure we understand each other. A shared network is where 
one collision domain (a physical network where devices can talk 
directly to each other without a router) has more than one IP subnet 
assigned on it.

The config option for this is shared-network and is used like this :

shared-network "x" {
   ... <shared-network specific options>
   subnet 192.168.2.0 ... {
     ... <subnet specific options>
   }
   subnet 10.0.0.0 subnet mask 255.255.255.128 {
     ...
   }
}

Also note that you cannot use 10.0.0.1 to 10.0.0.127 in a range in a 
/25 subnet. .127 is the broadcast address and so is not usable, and 
you MUST have a router in the subnet so that will require an IP 
address.
So you might put the router on 10.0.0.1 and use 10.0.0.2 to 
10.0.0.126 for your pool.

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Simon Hobson

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