Configuring System Interfaces for use with CDRouter Demo
CDRouter Demo utilizes three (3) network interfaces, at a minimum. Two are dedicated for use by the CDRouter software during testing. The third may be assigned to a live corporate or lab network connection, to allow remote access to the system running the CDRouter Demo software.
It is strongly recommended that the interface used for the connection to the corporate or lab network remains separate and not used as a test interface.
When a CDRouter Demo test package is run, it relies on the IP configuration information contained in the CDRouter configuration file, not on the Linux host. For this reason, you must have any network interfaces used as test interfaces be in an “unconfigured” state.
Step 1 - Determine the Ethernet Interface Names
As the root user, type the following command in a terminal window”
# ip link
This will return output similar to this: (the specific interface names may be different on your system)
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000 link/ether 00:03:2d:1a:cb:d5 brd ff:ff:ff:ff:ff:ff 3: enp0s8: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000 link/ether 00:03:2d:1a:cb:d6 brd ff:ff:ff:ff:ff:ff 4: enp0s9: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000 link/ether 00:03:2d:1a:cb:d7 brd ff:ff:ff:ff:ff:ff
In the example above, the 3 physical interfaces are named
Step 2 - Choose and Configure the Management Interface
For the following example, we are choosing
As the root user, use a text editor to create the file: /etc/sysconfig/network-scripts/ifcfg-enp0s3
*The name of the file must be: ifcfg-<interface-name-chosen-on-your-system>
DEVICE=enp0s3 TYPE=Ethernet NAME=enp0s3 ONBOOT=yes NM_CONTROLLED=yes USERCTL=yes IPV6INIT=no IPV6TO4INIT=no # For DHCP address: BOOTPROTO=dhcp PERSISTENT_DHCLIENT=yes
The values assigned to DEVICE and NAME must be the name of the interface chosen on your system.
To have this interface get an IPv4 address via DHCP, set BOOTPROTO to
Step 3 - Prevent Network Manager from Controlling the Other Interfaces
As the root user, use a text editor to create the file /etc/NetworkManager/conf.d/cdrouter.conf with the following contents:
[main] plugins=ifcfg-rh,keyfile [keyfile] unmanaged-devices=interface-name:enp*,except:interface-name:enp0s3;interface-name:cdreth*;interface-name:cdrtap*;interface-name:cdrbr*
The above configuration will tell Network Manager to control
enp0s3, but will
leave all other interfaces that begin with “enp”, unconfigured.
Step 4 - Restart Networking
You may need to restart networking to make changes take effect.
As the root user:
systemctl restart network