Netmask issue

Jeff Wieland wieland at purdue.edu
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 10.0.200.0 netmask 255.255.254.0 {
    range 10.0.200.10 10.0.201.254;

    option broadcast-address 10.0.201.255;
    option routers 10.0.200.1;
}

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



More information about the dhcp-users mailing list