DHCP Scopes with Cisco dhcp-relay

Discussion in 'Linux Networking' started by Matthew Reath, Aug 18, 2004.

  1. I am currently looking into a replacement for some Cisco CNR servers
    and would like to use dhcpd under Linux but have a few things to work
    out first and was hoping I can get some help on the list.

    Basically I have an interface configured as follows:

    interface GigabitEthernet0/1
    ip address 192.168.1.1 255.255.255.0
    ip address 172.16.0.1 255.255.0.0 secondary

    I have dhcp-relay configured to forward dhcp requests to my dhcp
    server. Because of the nature of DHCP/BOOTP all of the requests look
    as though they are coming from the 192.168.1.0 subnet and thus thats
    what my dhcp server replies back with.

    Using Cisco CNR you can configure secondary pools. For example in this
    case I would configure the 172.16.0.0 network as a secondary pool of
    192.168.1.0. The end result is when all of the 192.16.1.0 addresses
    get assigned it will start handing out 172.16.0.0 addresses.

    Does anybody know of a way to configure this using dhcpd (dhcpd.conf)?

    I would really like to figure this out but have not found much in the
    man page for dhcpd.

    Thanks,
    Matt
     
    Matthew Reath, Aug 18, 2004
    #1
    1. Advertisements

  2. Matthew Reath

    vhu Guest

    You should use 'shared-network'. The basic idea goes like this:

    shared-network gi0_1 {
    subnet 192.168.0.0 netmask 255.255.255.0 {
    }
    subnet 172.16.0.0 netmask 255.255.0.0 {
    }
    }

    You just don't define any ranges to 192.168.0, if there is a range
    defined in 172.16 dhcpd will use that to hand out the addresses.
     
    vhu, Aug 18, 2004
    #2
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.