Create Linux/Networking Bridge

Follow these instructions to create a networking bridge.

1. Log in to the KVM server.
2. Create a file called ifcfg-lanbrN and replace N with the interface number under /etc/sysconfig/network-scripts/ .
3. Open the file in an editor and enter the following

   [localadmin@localhost network-scripts]$ cat ifcfg-lanbr201
   DEVICE=lanbr201
   TYPE=Bridge
   BOOTPROTO=none
   ONBOOT=yes
   DELAY=0
   [localadmin@localhost network-scripts]$
   

4. To add the virtual interface to the LAN bridge, ensure ONBOOT=yes and BRIDGE=the name of the LAN bridge in the ifcfg-ens2f0 file, where ifcfg-ens2f0 is the virtual interface.

   [localadmin@localhost network-scripts]$ cat ifcfg-ens2f0
   TYPE=Ethernet
   PROXY_METHOD=none
   BROWSER_ONLY=no
   BOOTPROTO=dhcp
   DEFROUTE=yes
   IPV4_FAILURE_FATAL=no
   IPV6INIT=yes
   IPV6_AUTOCONF=yes
   IPV6_DEFROUTE=yes
   IPV6_FAILURE_FATAL=no
   IPV6_ADDR_GEN_MODE=stable-privacy
   NAME=ens2f0
   UUID=bf4196e3-b003-41ff-8b02-29ed79ea3552
   DEVICE=ens2f0
   ONBOOT=yes
   BRIDGE=lanbr201
   [localadmin@localhost network-scripts]$
   

5. Create a WAN bridge by logging into the KVM server.
6. Create a file called ifcfg-wanbrN and replace N with the interface number under /etc/sysconfig/network-scripts.
7. Open the file in an editor and enter the following.

   [localadmin@localhost network-scripts]$ cat ifcfg-wanbr201
   DEVICE=wanbr201
   TYPE=Bridge
   BOOTPROTO=none
   ONBOOT=yes
   DELAY=0
   [localadmin@localhost network-scripts]$
   

8. To add the virtual interface to the WAN bridge, ensure ONBOOT=yes and BRIDGE=the name of the WAN bridge in the ifcfg-ens2f1 file, where ifcfg-ens2f1 is the virtual interface.

   [localadmin@localhost network-scripts]$ cat ifcfg-ens2f1
   TYPE=Ethernet
   PROXY_METHOD=none
   BROWSER_ONLY=no
   BOOTPROTO=dhcp
   DEFROUTE=yes
   IPV4_FAILURE_FATAL=no
   IPV6INIT=yes
   IPV6_AUTOCONF=yes
   IPV6_DEFROUTE=yes
   IPV6_FAILURE_FATAL=no
   IPV6_ADDR_GEN_MODE=stable-privacy
   NAME=ens2f1
   UUID=f45577ab-f733-4c53-a791-fe44662cc5b4
   DEVICE=ens2f1
   ONBOOT=yes
   BRIDGE=wanbr201
   [localadmin@localhost network-scripts]$
   

9. Restart the network by entering the following.

   $sudo systemctl restart network

10. Verify the interfaces are connected to the bridges by entering the following.

    $sudo brctl show

    The interfaces should look like the following

    [localadmin@localhost network-scripts]$ brctl show
    bridge name     bridge id               STP enabled     interfaces
    lanbr201        8000.3cfdfe6272a8       no              ens2f0
                                                            vnet0
    lanbr202        8000.3cfdfe6272aa       no              ens2f2
                                                            vnet1
    lanbr203        8000.3cfdfe6272b8       no              ens3f0
                                                            vnet2
    
    wanbr201        8000.3cfdfe6272a9       no              ens2f1
                                                            vnet3
    wanbr202        8000.3cfdfe6272ab       no              ens2f3
                                                            vnet4
    wanbr203        8000.3cfdfe6272b9       no              ens3f1
                                                            vnet5
                                                            vnet6
    [localadmin@localhost network-scripts]$