[Dnsmasq-discuss] Problem when WinXP firewall is activated (d
oes not reply to ping)
raphael.huck at efixo.com
Sun Dec 3 09:49:49 GMT 2006
>>>As I understand it, the client should try an arping before using the
>>>address it has been given by the server.
>>>The interesting question is whether WinXP actually implements this
>>>arping. If Windows follows the specification on this, there should be
>>>no point in the server using arping.
>> I'm going to check if WinXP does the arping check.
DHCP client computers running Windows 2000 or Windows XP that obtain an IP
address use a gratuitous ARP request to perform client-based conflict
detection before completing configuration and use of a server offered IP
address. If the DHCP client detects a conflict, it will send a DHCP decline
message (DHCPDECLINE) to the server.
So it seems that Windows XP does an ARP check before using an IP address.
I'll check that with Wireshark on Monday.
>> But the other problem with a SOHO including a DHCP server is that a SOHO
>> is often rebooted (because the user changed settings which require a
>> reboot, because of a power failure,...).
>> So each time it reboots, the lease file is cleared.
>Which is a bug in the SOHO. Assuming by SOHO you mean WRT-54G-class
>stuff, then you might like to consider moving to DD-WRT. I worked with
>them to add hooks into dnsmasq so that the lease file can be stored in
>the non-volatile RAM and not trashed on a reboot. You might also like to
>consider asking the developers of your current firmware to implement the
Could you give me pointers on how to do that?
Is it always safe to reload an old lease file on reboot?
>> I have the issue only in this case: the SOHO reboots, the WinXP PC
>> (firewall enabled) has 192.168.1.20, the Linux PC also has 192.168.1.20,
>> and in the lease file of dnsmasq, 192.168.1.20 corresponds to the MAC
>> address of the WinXP PC.
>That does look like WinXP might be broken: I'd be interested in the
>results of your tests.
Again, I'll have to check with Wireshark on Monday. Why do you think it's
WinXP the problem?
More information about the Dnsmasq-discuss