Static Routes via DHCP - How to do?

[David Hoffman]

On Wed, 26 Jan 2005 15:03:29 +0100, Roger Grosswiler <roger at gwch.net> wrote:
> Hi,
> 
> I use 4 networks in total:
> 
> 10.0.0.0/8
> 192.168.0.0/24-->default route
> 192.168.1.0/24
> 192.168.2.0/24
> 192.168.3.0/24
> 
> All clients are in network 10.0.0.0/8, where i give them ip-adresses and
>  default-gateway via dhcp.
> 
> I look now for something, where i can add static routes to the
> dhcp-configuration, so all clients in 10.0.0.0/8 get route-entries for
> the default-route (specified, works) AND the routes for the other
> networks. I googled around and found an entry option static-route
> [ip-adress ip-adress, ip-adress ip-adress] but i still did not get this
> running.
> 

There is an "option static-route" in the dhcpd.conf file, but from
what I read on several sites that I just googled (have you googled
this?) it is sometimes client-dependent. In other words, the client
may not support the option.

In any case, how many NIC cards do your clients have? If they only
have one, then there can only be one route out of the machine. All
your clients on the 10.0.0.0/8 network need to route their traffic
either to a gateway or to the rest of the network. Of course they
already know that other traffic on the 10.0.0.0 network should be
routed out the same interface, but where does traffic to the other 4
networks go? Probably out the same interface. Then it's the ROUTER
that decides where to send the packets after that.

Look at it this way... when you are on your home machine, and you dial
up to the internet, you have 1 route that says anything not on your
home machine goes to your ISP. Then your ISP's router looks at the
destination-ip and decides where to route from there. You don't get
separate routes in your machine for every path you want to take.

Unless you have machines with more than one NIC, you only need one
default route for all traffic not on the same network.