[Dnsmasq-discuss] about 2.38
simon at thekelleys.org.uk
Sun Feb 18 19:44:44 GMT 2007
Carlos Carvalho wrote:
Thanks for those, I'll fix them in the source tree.
> "This is sometimes needed, for example when sending options to
> I hope the client knows how to handle these extra options. Can you
> give an example of which option is not asked for but necessary and
There's an example in dnsmasq.config.example
# Send options to PXELinux. Note that we need to send the options even
# though they don't appear in the parameter request list, so we need
# to use dhcp-option-force here.
# See http://syslinux.zytor.com/pxe.php#special for details.
# Magic number - needed before anything else is recognised
# Configuration file name
# Path prefix
# Reboot time. (Note 'i' to send 32-bit value)
The DHCP interaction is done by the PXE ROM, which passes control to
PXELinux, so the options required for PXELinux are not known when DHCP
is done. The URL gives details: on the ISC server the trick is to append
the options to the requested option list. dhcp-option-force provides the
same facility for dnsmasq.
> I've carefully built configs for each machine specifying exactly the
> options I want sent. It's important to know what is really sent. I'd
> like to have a debug/trace option to see "sending option <no.>=xyz" in
> the logs so that I can choose between dhcp-option and
If you ensure that hosts which don't need it don't get the dhcp-boot
setting then 2.38 gives 192 bytes of extra option space by re-using the
filename and servername fields.
A log option sound useful and easy and small, I'll add it to next
release. Probably only option number and size: the formats are to
varied to print sucessfully without code bloat.
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