data-expr question

[Philip A. Prindeville]

Asked and answered.

The correct syntax is:

send dhcp-client-identifier = hardware;

though in honesty that's less than obvious from the documentation. 
Perhaps an example of using data-expr's other than conditional blocks
and option xxx = yyyy would make this more apparent?



On 01/28/2010 11:41 AM, Philip A. Prindeville wrote:
> Hi.
>
> I've not hacked dhcp clients or servers since RFC-1048, so I'm a little
> rusty...
>
> I'm using dhclient-4.1.0 on Fedora Core 12 (updated), and we use a
> variety of devices (bridges of the Ethernet/Wifi and Ethernet/DOCSIS)
> variety that invariably munge the source address on DHCP packets when
> forwarding (don't know why).
>
> As a workaround, I need to send the client-identifier which the bridge
> *won't* munge, but don't want to explicitly give it in each config file
> because that's unmanageable.
>
> I tried:
>
> send dhcp-client-identifier hardware;
>
> but this, of course, didn't work because the client doesn't do data-expr
> evaluation on this command.
>
> What would be involved in adding that, or simply adding a switch that
> makes this behavior the default?
>
> And if I submitted a patch for the latter, would it likely be accepted?
>
> We don't want to run patched sources whenever possible... the former is
> more generically useful and hence more likely to be accepted, but it's
> also a lot more churn on code that I've never looked at before.
>
> Thanks,
>
> -Philip
>
>