Hi
I'm running CentOS 7 with KVM with a static IP. On the CentOS machine I am running 2 guests with Ubuntu 14.04, with public static IPs. I can't upgrade Ubuntu for software reasons.
I set up 2 bridges and 2 routes on the CentOS to enable the 2 guests to connect to the internet and all works well.
However, I want the 2 guests to be able to talk to each other via their respective IP addresses and I can't get that to work. Please help!
I tried to connect both guests to the same bridge and that works for communicating between the guests, but then one of the guests loses Internet connectivity.
Thank you
Georg

Do you use libvirt or raw kvm? In the former case, create a network e.g. virsh net-create, then connect the guests to it. In the latter case, provide details about the guests' network connections and the routes you created.

If a guest loses internet connection when both guests are connected to the same bridge, something is wrong.

I used raw kvm on the centOS and virt-manager for the guests.
The CentOS (xx.xx.xx.69) has the following configurations:

# /etc/sysconfig/network-scripts/ifcfg-br0
DEVICE=br0
ONBOOT=yes
TYPE="Bridge"
BOOTPROTO=static
IPADDR=xx.xx.xx.69
NETMASK=255.255.255.255
STP=off
DELAY=0
ZONE=public

# /etc/sysconfig/network-scripts/route-br0
ADDRESS0=xx.xx.xx.117
NETMASK0=255.255.255.255
#GATEWAY0=xx.xx.xx.69

# /etc/sysconfig/network-scripts/ifcfg-br1
DEVICE=br1
ONBOOT=yes
TYPE="Bridge"
BOOTPROTO=static
IPADDR=xx.xx.xx.69
NETMASK=255.255.255.255
STP=off
DELAY=0
ZONE=public

# /etc/sysconfig/network-scripts/route-br1
ADDRESS0=xx.xx.xx.111
NETMASK0=255.255.255.255
#GATEWAY0=xx.xx.xx.69

On the guests I use the virt-manager configuration:

xx.xx.xx.117 uses Bridge br0: Host device vnet0
xx.xx.xx.111 uses Bridge br1: Empty bridge

This is the other part I am puzzled with: Why is the br1 empty? It is set up exactly like br0.

Thank you very much for your help.