Netmask issue

Jeff Wieland wieland at
Tue Oct 6 12:39:22 UTC 2009

Reissom Beshir wrote:
> Simon Hobson wrote:
>>> So does this bug exist in dhcp-4.0?
>> Is it a bug ? The OP didn't specify a netmask option to send to 
>> clients. You could argue that the logic is wrong in how the value is 
>> chosen, but if the admin specifies the right value then it works just 
>> fine.
> Whether it is a bug or not, does this behaviour exist in dhcp-4.0?
> Please inform.
> Thanks,
> Reissom

Did we ever see the dhcpd.conf file?  My guess here is that
somewhere there is an "option subnet-mask" outside of the

subnet netmask {

    option broadcast-address;
    option routers;

that is overriding the netmask part of the subnet statement,
perhaps in a group that the subnet statement is within.  We've been
bit by this.  What I do is to *never* use an "option subnet-mask"
statement, and just let the subnet statement handle it, *unless*
you have a subnet that needs a different mask, and then (and only
then) I assign it with "option subnet-mask".
           Jeff Wieland            |         Purdue University
    Network Systems Administrator  |        ITN&S Data Networks
        Voice: (765)496-8234       |        501 Harrison Street
         FAX: (765)494-6620        |   West Lafayette, IN 47907-2025

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