[Dnsmasq-discuss] PXE service across subnets
GARRISON, TRAVIS J.
garrisot at otc.edu
Fri Dec 3 22:49:21 GMT 2010
>>>> We have tried searching but we could not find an answer to our
>>>> problem. Our clients cannot pxe boot from our dnsmasq server across
>>>> different subnets. We have the dnsmasq server configured to proxy
>>>> the dhcp requests to our main dhcp server. We have created helper
>>>> addresses for both the dhcp and pxe server on the different subnets.
>>>> Pxe booting works fine when on the same network. What are we
>>> Is anything logged by dnsmasq? The DHCP helper function needs to
>>> relay broadcasts to both servers. Are you sure that the switches can
>>> do that?
>> We did a packet capture on the dnsmasq server and tried to pxe boot
>> one of our clients. We can see 3 DHCP Discover requests come in from
>> the 172.25.16.0 subnet, which would be our client, but we see no
>> response from the dnsmasq server. We have the option
>> dhcp-range=172.25.16.0,proxy set. Our networks are in the
>> 255.255.252.0 subnet range, would that have any problems?
>Ah, lightbulb. This extract from the man page is relevant:
>"For directly connected networks (ie, networks on which the machine running dnsmasq has an interface) the netmask is optional. It is, however, required for networks which receive DHCP service via a relay agent."
>So your dhcp-range line should be
Ah ha, that fixed it, thank you big time :)
More information about the Dnsmasq-discuss