Re: [Qemu-devel][PATCH] Built-in DHCP server

[Kazu]

Sent: Tuesday, February 20, 2007 11:22 PM Lonnie Mendez wrote:


> On Tue, 2007-02-20 at 13:09 +0900, Kazu wrote:
>> Hi,
>>
>> After I used TAP device by -net nic -net tap,ifname=mytap and I tried to
use
>> user mode network by -net nic -net user, a Windows XP guest doesn't get
>> IP address from a built-in DHCP server.
>>
>> It is fixed by an attached patch.
>>
>> DHCPRELEASE and DHCPNACK are introduced.
>>
>> DHCPRELEASE code is borrowed from VirtualBox. Windows 2000/XP tries to
call
>> DHCPREQUEST and get old IP address when it boots. I made a code to reply
>> DHCPNACK to the request. Then the Win2k/XP called DHCPDISCOVER and try to
>> get a new IP address.
>>
>> I tested Windows 98SE/2000/XP, Knoppix 3.8, Morphix, Fedora Core 3 and
>> RedHat 7.2 guest.
>> There is not problem except RH7.2. It can get IP address but it is
>> 10.0.2.16. dhcpcd in RH7.2 tries to call DHCPDISCOVER two times. So it
>> consumes two entries in the built-in DHCP server. It seems that it is a
bug
>> of dhcpcd in RH7.2.
>
> This is nice.  One regression noticed is windows 98 SE with the ne2k_isa
> card.  It used to obtain an ip address at boot time without this patch -
> now it obtains a garbage address 169.x.x.x.  Works great with ne2k_pci.
>

Thank you for your information. I tested ne2k_isa. The problem is that DHCP
packet is received only one time, if ne2k_isa is used. It is strange that
once DHCP paket is received, no more packet appear in DHCP server and
Win98SE geust. So Win98SE holds old IP address if without patch. I found
that -net nic,model=ne2k_isa -net user works but -M isapc option stops QEMU
with unhandled Win32 exception. It seems that ISA emulation is broken
somewhere.

Regards,
Kazu