Thanks for your instructions, Stefan. Wireshark showed me that in DHCPOFFER and DHCPACK there are given the DNS server and the router addresses. Then I saw that the CentOS installer uses the assigned IP address to query the 10.0.2.3 DNS server. So the CentOS insaller got the DNS address and uses it to try to reverse-resolve its IP (10.0.2.15) address.
Why the installer logs "DHCPv4 eth0 - option routers: ", i.e. no routers, that I don't know. Moreover, why the installer logs "no DNS servers, can't look up hostname" I also don't know. It was given the address, and it even used the server. I interpreted "can't look up hostname" as "can't look up some hostname", while it probably means "can't figure out my hostname". In my previous tests I didn't continue, because I assumed something went wrong, but now I tried again, and things just work: the installer can resolve names and reach the Internet. In conclusion, I raised a false alarm based on the CentOS installer messages, and with more debugging, it turns out that QEMU works fine. Thank you, Stefan, for your help. I'm happy now. Best, Irek (irkos.org) -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/577908 Title: qemu 0.12.3 default networking DNS broken Status in QEMU: Incomplete Bug description: This might be something simple and known, but I don't find such information... I installed qemu 0.12.3 from source on a Linux/x86-64 host and observe that, running a debian testing guest (squeeze netinst, also the installed system), the DNS setup that qemu's DHCP provides is not working. Namely, nameserver 10.0.2.3 in /etc/resolv.conf (as created by DHCP) does not help name resolution, but replacing the IP with my actual DNS server does work. Now this is still unfortunate as it is very cumbersome to replace the DNS for every system I run in qemu for testing... it used to work before with earlier versions. If there is some easy means to help debug this, I'll try to help... but right now I am rather clueless.
