how to configure DHCP relay with ISC.

[Simon Hobson]

Guo, Fei wrote:

>   can you give me an example about how to configure on the 
>client/relay/server side, I have installed 4.1.1 version, a 
>simple topology is the following:
>
>   client ------------------------------------------  relay 
>------------------------------------------ server
>        eth1                              192.168.1.2 
>192.168.2.2             192.168.2.1
>
>   I want get a IP address on client "eth1", it should be in net 
>"192.168.1.x/24". thank you very much.
>

Client: you don't need to do anything, the default install should work.
Server: You don't have to do anything special, just define the subnet 
and an appropriate range and options.

Relay agent: Not sure about that (I haven't used it myself) - you'll 
have to read the man pages unless someone else pops up to answer.

A bit more abut the server config. For technical reasons, you must 
define the subnet that the server is in (even if it's empty), so 
you'll have something like :

<global options>
subnet 192.168.1.0 ... {
   <subnet options>
   range 192.168.1.x 192.168.1.y ;
}
subnet 192.168.2.0 ... {
}

The assignment of clients to subnet is automagic - the relay agent 
adds information to the packets that the server can use to identify 
the client subnet, the rest "just happens".

-- 
Simon Hobson

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