[Dnsmasq-discuss] disable Router does not work
simon at thekelleys.org.uk
Fri Aug 25 15:10:16 BST 2006
Jürgen Steinel wrote:
> today I wanted to disable routing for a single host. That machine gets
> its IP from dnsmasq.
> In the dnsmasq.conf I added an entry to assign the host to a
> network-group and set an option for this group that should disable the
> Unfortunately this did not have the expected effect. The host got the IP
> mentioned in dhcp-host but was still told where the (actual) router is.
> I captured the dhcp-request/reply to make sure the Information came from
> dnsmasq (and was not cached by the client). Dnsmasq *did* deliver the
> To test if dhcp-option does anything at all I changed the above line to
> After requesting a new IP the client got 188.8.131.52 as default gateway.
> I think this behaviour is wrong (=ignore option if given IP is 0) and
> even if it is intented it should be mentioned in the manual.
> Is there a different way to set an option to a zero-value?
Using 0.0.0.0 doesn't work, since that's used as shorthand for "the
address of the host running dnsmasq" - you saw this in your experiments.
For most DHCP options, doing
will send the option, with no extra data, but for the four special
options which dnsmasq sends by default (router, DNS server, netmask and
broadcast address) then doing
completely suppresses sending the default.
I hope that this is actually more logical than my explanation of it....
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