Dear Linux Gurus
I'm having problems with KVM and networking. My guest cannot use NAT through the host's connection. This is what I've done:
I installed a new version of Centos 6.5 on the hardware. Starting with a Net-Install, I selected the Virtual Hosting, and later added "Desktop". I ran "yum update" with some reboots until nothing needed updating.
The host networking is IPV4 only, using DHCP. (A different box on my home network provides DHCP and is a gateway to the internet. I have a reservation in that DHCP so that the host always gets a known IP address)
Using a Gnome desktop, as a non-root user, I installed Windows 7 Pro from an image of an ISO I had copied onto the host. In the "Networking" configuration, I chose "DEFAULT". The documentation of KVM seems to imply that it should give me a NAT'ted interface to my host's connection (I wasn't worried about performance at this point).
When the installation was complete, Windows tries to configure the network. Running the Windows command line "IPCONFIG" program, the Windows guest program does get an IP address from the host (192.168.122.xxx), but the guest cannot communicate to the outside world. I can ping the host, but nothing else.
Is there some other magic sauce, perhaps in the IPTABLES of the host, that will allow the guest to use the internet? I'm baffled.
On the KVM host, this is the result of "iptables -L"
--------------------------------------
Chain INPUT (policy ACCEPT) target prot opt source destination ACCEPT udp -- anywhere anywhere udp dpt:domain ACCEPT tcp -- anywhere anywhere tcp dpt:domain ACCEPT udp -- anywhere anywhere udp dpt:bootps ACCEPT tcp -- anywhere anywhere tcp dpt:bootps ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT icmp -- anywhere anywhere ACCEPT all -- anywhere anywhere ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:ssh REJECT all -- anywhere anywhere reject-with icmp-host-prohibited
Chain FORWARD (policy ACCEPT) target prot opt source destination ACCEPT all -- anywhere 192.168.122.0/24 state RELATED,ESTABLISHED ACCEPT all -- 192.168.122.0/24 anywhere ACCEPT all -- anywhere anywhere REJECT all -- anywhere anywhere reject-with icmp-port-unreachable REJECT all -- anywhere anywhere reject-with icmp-port-unreachable REJECT all -- anywhere anywhere reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT) target prot opt source destination
-------------------------------------
Thanks for your help.
David
On Fri, Feb 21, 2014 at 1:55 PM, david david@daku.org wrote:
Dear Linux Gurus
I'm having problems with KVM and networking. My guest cannot use NAT through the host's connection. This is what I've done:
I installed a new version of Centos 6.5 on the hardware. Starting with a Net-Install, I selected the Virtual Hosting, and later added "Desktop". I ran "yum update" with some reboots until nothing needed updating.
The host networking is IPV4 only, using DHCP. (A different box on my home network provides DHCP and is a gateway to the internet. I have a reservation in that DHCP so that the host always gets a known IP address)
Using a Gnome desktop, as a non-root user, I installed Windows 7 Pro from an image of an ISO I had copied onto the host. In the "Networking" configuration, I chose "DEFAULT". The documentation of KVM seems to imply that it should give me a NAT'ted interface to my host's connection (I wasn't worried about performance at this point).
When the installation was complete, Windows tries to configure the network. Running the Windows command line "IPCONFIG" program, the Windows guest program does get an IP address from the host (192.168.122.xxx), but the guest cannot communicate to the outside world. I can ping the host, but nothing else.
Is there some other magic sauce, perhaps in the IPTABLES of the host, that will allow the guest to use the internet? I'm baffled.
Do you have ip_forwarding enabled in sysctl?
https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/...
On 2/21/2014 11:55 AM, david wrote:
I'm having problems with KVM and networking. My guest cannot use NAT through the host's connection.
did you configure the KVM host to use bridging for the virtual network ? in this scenario, the KVM host is using br0 instead of eth0 for its own networking, eth0 and the virtual network are both bridged by br0. in this configuration, your VMs appear to be on your LAN same as other non-VM systems, they'd get their DHCP stuff from the existing gateway router, etc.
-
david -
John R Pierce -
Les Mikesell