[Qemu-devel] SLIRP's DNS problem

[Qemu-devel] SLIRP's DNS problem

[Irek Szczesniak]

Hi,

I have a problem with the SLIRP's DNS server.  I built from sources
QEMU v 0.13 on Linux debian 2.6.26-2-686 with gcc version 4.3.2
(Debian 4.3.2-1.1).

When I don't pass any network options to QEMU, then I should get a
user networking with SLIRP. According to the man page, QEMU should
create a private network 10.0.2.0/24, and run a DHCP server on
10.0.2.2, and a DNS server on 10.0.2.3.  And indeed such a network is
created, the DHCP server assigns the 10.0.2.15 IP address, but in the
DHCP transaction it seems there is no DNS server mentioned, and my
system complains about a missing DNS server.

Let me describe how I got this problem.  I start the CentOS installer this way:

qemu -cdrom CentOS-5.5-i386-netinstall.iso

The installer runs, asks questions, and something goes wrong.  On the
third console (Alt + F3 in the virtual machine), I can read errors:

DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6
DHCPOFFER from 10.0.2.2
DHCPREQUEST on eth0 to 255.255.255.255 port 67
DHCPACK from 10.0.2.2
bound to 10.0.2.15 -- renewal in 33026 seconds.
DHCPv4 eth0 - obtained lease 10.0.2.15
DHCPv4 eth0 - option subnet-mask: 255.255.255.0
DHCPv4 eth0 - option subnet-mask: - prefix_len: 24 broadcast: 10.0.2.255
DHCPv4 eth0 - option routers:
no DNS servers, can't look up hostname

The installer complains that a DNS server is missing, but it seems
that the DHCP also doesn't provide a default gateway.

I would appreciate it if someone could help me in resolving this problem.


Thanks,
Irek
http://irkos.org

Re: [Qemu-devel] SLIRP's DNS problem

[Mulyadi Santosa]

Hi...

On Thu, Dec 23, 2010 at 20:49, Irek Szczesniak
<irek.szczesniak@gmail.com> wrote:
> DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6
> DHCPOFFER from 10.0.2.2
> DHCPREQUEST on eth0 to 255.255.255.255 port 67
> DHCPACK from 10.0.2.2
> bound to 10.0.2.15 -- renewal in 33026 seconds.
> DHCPv4 eth0 - obtained lease 10.0.2.15
> DHCPv4 eth0 - option subnet-mask: 255.255.255.0
> DHCPv4 eth0 - option subnet-mask: - prefix_len: 24 broadcast: 10.0.2.255
> DHCPv4 eth0 - option routers:
> no DNS servers, can't look up hostname
>
> The installer complains that a DNS server is missing, but it seems
> that the DHCP also doesn't provide a default gateway.


what if you specificly mention the network type like below:

qemu-kvm -cdrom centos-netinstall -net nic,model=e1000 -net user

will it make any difference?

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com

Re: [Qemu-devel] SLIRP's DNS problem

[Ireneusz Szcześniak]

Thanks for your interest.

Mulyadi Santosa wrote:

>> The installer complains that a DNS server is missing, but it seems
>> that the DHCP also doesn't provide a default gateway.
> 
> what if you specificly mention the network type like below:
> 
> qemu-kvm -cdrom centos-netinstall -net nic,model=e1000 -net user
> 
> will it make any difference?

Unfortunately, no difference.

-- 
Ireneusz (Irek) Szczesniak
http://www.irkos.org