Steve, Try the following config. On your host: /etc/sysconfig/network-scripts/ifcfg-eth0 : DEVICE=eth0 BOOTPROTO=none ONBOOT=yes NM_CONTROLLED=no TYPE=Ethernet HWADDR=xx:xx:xx:xx:xx:xx <- put your physical NIC's MAC address here BRIDGE=br0 USERCTL=no IPV6INIT=no IPV6_AUTOCONF=no /etc/sysconfig/network-scripts/ifcfg-br0 : DEVICE=br0 BOOTPROTO=static ONBOOT=yes NM_CONTROLLED=no TYPE=Bridge IPADDR=10.0.5.16 NETMASK=255.255.255.0 <- you may need to adjust this to your network GATEWAY=10.0.5.1 DNS1=8.8.8.8 DNS2=8.8.4.4 PEERDNS=yes DELAY=0 STP=off USERCTL=no IPV6INIT=no IPV6_AUTOCONF=no Restart networking on the host. Then inside you VM: /etc/sysconfig/network-scripts/ifcfg-eth0 : DEVICE=eth0 BOOTPROTO=static ONBOOT=yes NM_CONTROLLED=no TYPE=Ethernet HWADDR=xx:xx:xx:xx:xx:xx <- it must be a unique MAC address for your VM IPADDR=10.0.5.17 NETMASK=255.255.255.0 <- you may need to adjust this to your network GATEWAY=10.0.5.1 DNS1=8.8.8.8 DNS2=8.8.4.4 PEERDNS=yes USERCTL=no IPV6INIT=no IPV6_AUTOCONF=no Then in Virtual Machine Manager make sure that your VM's NIC is connected to the br0 bridge, like this: Network Source: Specify shared device name Bridge Name: br0 On 6/10/2014 8:16 PM, Steve Campbell wrote: > On 6/10/2014 12:43 PM, Digimer wrote: >> On 10/06/14 12:38 PM, Steve Campbell wrote: >>> On 6/10/2014 12:05 PM, Digimer wrote: >>>> On 10/06/14 11:46 AM, Steve Campbell wrote: >>>>> On 6/10/2014 10:46 AM, Digimer wrote: >>>>>> On 10/06/14 10:03 AM, Steve Campbell wrote: >>>>>>> I had so much trouble putting Centos 6 guest VMs on a Centos 5 host >>>>>>> that >>>>>>> I finally switched to a Centos 6 host. >>>>>>> >>>>>>> I've not needed more that test VMs, so I've used Virtual Machine >>>>>>> Manager >>>>>>> on the old system, which worked pretty well, so I decided to >>>>>>> create my >>>>>>> first KVM guest machine. I noticed when I created it, I only had the >>>>>>> options of NAT for my network interface, so I used that (obvious). >>>>>>> >>>>>>> Well, after starting the VM, I find I don't have connectivity with >>>>>>> that >>>>>>> interface. Reading, I find examples where I need to create bridges >>>>>>> perhaps. Xen did most of this for me, so it's a little new to me. >>>>>>> >>>>>>> Can anyone throw me a clue, please? >>>>>>> >>>>>>> steve campbell >>>>>> Setting up a bridge is not that hard, and it will give your VMs >>>>>> direct >>>>>> access to the outside world, and host <-> VM access just fine as >>>>>> well. >>>>>> >>>>>> Here is a link showing how to setup a bridge connected to a bond >>>>>> device. Ignore the bond and pretend it is a straight ethX device: >>>>>> >>>>>> https://alteeve.ca/w/AN!Cluster_Tutorial_2#Configuring_our_Bridge.2C_Bonds_and_Interfaces >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>> The host has a device named virbr0 that is installed during system >>>>> installation. It also has a network device vnet0. There are no >>>>> files in >>>>> /etc/sysconfig/network-scripts for these. >>>>> >>>>> Shouldn't I be able to use the virbr0 virtual bridge for this? I've >>>>> tried setting up the VM's device with all of the options that is >>>>> listed, >>>>> but to no avail. >>>>> >>>>> Should I need to set up another bridge for this? >>>>> >>>>> And thanks for the link. >>>>> >>>>> steve >>>> virbr0 is created and managed by libvirtd. If you open Virtual Machine >>>> Manager, connect to localhost and then double-click on 'localhost', >>>> you will see a tab for creating/managing bridges (NAT'ed, generally). >>>> I disable 'virbr0' as NAT'ing is generally not what I want. >>>> >>>> The 'vnetX' devices are dynamically created to link a VM's interface >>>> to a bridge. Think of them as virtual network cables. They get created >>>> and destroyed as needed. >>>> >>>> >>> Sorry, but I'm confused: >>> >>> My host server has a real NIC and IP address with a real gateway to the >>> outside: >>> virtbr0 IP: 192.168.122.1 >>> Host IP: 10.0.5.16 >>> Gateway IP: 10.0.5.1 >>> on eth0 and this works >>> >>> My VM server has all fake stuff currently: >>> Host IP: 10.0.5.17 >>> Gateway IP: 10.0.5.1 >>> on eth0 and this is like NIC without a cable. >>> >>> So I need to create a bridge device on both the host and VM (lets say I >>> name it br1). I change the eth0 config file on both host and VM to point >>> to br1 and give the br1 config file on both host and VM the correct IP. >>> But won't this just let the two talk to each other. How will the VM >>> server get outside? >>> >>> steve >> The bridge is created only on the host. Think of the bridge as being >> like a virtual switch. When a VM is created, you tell it to connect to >> the bridge, similar to how you would plug a physical wire into a real >> switch. That provides the link to the network, and then you configure >> the virtual server's network just as if it was a real network. >> >> On the host, you don't set the IP on the ethX device, instead you tell >> ethX to connect to the bridge (look at 'bond2' in the link above for >> the 'BRIDGE="..."' line). Then you move the host's IP address/config >> to the bridge itself (look at the 'vbr2' in the link above). >> >> If you're still stuck, tell me the IP addresses you want to set in the >> host and VM and I'll see if I can bang out a couple sample 'ifcfg-X' >> files. >> > I'm running into some problems with my config files where I get a > message that says the network can't determine my interface names. I'll > look further, but the IPs above are what I need. 10.0.5.1 is a firewall > that NATs the 10.0.5.0/24 network to another outside public firewall. > > Thanks > steve > _______________________________________________ > CentOS-virt mailing list > CentOS-virt at centos.org > http://lists.centos.org/mailman/listinfo/centos-virt >