[CentOS] KVM host question about host firewall

Wed Jan 19 05:16:38 UTC 2011
Gordon Messmer <yinyang at eburg.com>

On 01/18/2011 02:21 PM, Kwan Lowe wrote:
>
>     Yesterday I was troubleshooting an issue with a KVM host. I was
> unable to access the DNS service on a KVM virtual machine. After
> verifying that the vm allowed through the DNS ports (53 on UDP/TCP)
> and still being unable to access, I was able to connect immediately
> after allowing those ports on the KVM host.  Is there anyway around
> this?  The reason is that I would like to allow only SSH access to the
> host, but allow other services to the virtual machines.

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/Virtualization/sect-Virtualization-Network_Configuration-Bridged_networking_with_libvirt.html

If you have your networking set up as Red Hat advises, the host's 
firewall will not affect guests.  Those systems will be responsible for 
their own firewalling.