[Dnsmasq-discuss] Restrict dhcpd listening interfaces.
lists at wildgooses.com
Wed Mar 28 12:23:05 BST 2012
On 27/03/2012 21:49, Simon Kelley wrote:
> On 27/03/12 15:18, Simon wrote:
>> The strange packets have source address 0.0.0.0 and/or destination
>> address 255.255.255.255. When an socket is bound to a particular
>> address, it may not receive these packets. Some kernels work fine,
>> but it's really moving into undefined territory and portable code
>> which works everywhere is much easier when binding the wildcard.
> As an example of the sort of trouble you can get into with this, imagine
> a physical network interface with two IP addresses, say
> 192.168.1.1 and 192.168.2.1
> Now start two different instances of a DHCP server, one bound to
> 192.168.1.1 and the other bound to 192.168.2.1
> A client on the network attached to the interface now starts DHCP by
> broadcasting to 255.255.255.255. Which DHCP server instance should reply?
Surely that specific problem is just badly phrased - the situation is no
different whether you have two instances on one machine or two instances
on two machines? The problem there is that you have two instances
listening to a broadcast address? (ie it would make no odds if you have
two instances bound to 0.0.0.0 or bound to something else - the issue is
the two instances?)
Wasn't the original question the difference between binding to 0.0.0.0
vs binding to each interface individually?
More information about the Dnsmasq-discuss