Networking Quirk in CentOS 7 - Virtual IP not being assigned
by Alpha01
I just realized the order of which the IP configurations are set in the /etc/sysconfig/networking-scripts/ifcfg-* file does matter. For example the following config was failing to assign the virtual IP 192.168.100.218 on one of my systems:
TYPE="Ethernet"
BOOTPROTO="static"
IPADDR=192.168.100.218
NETMASK=255.255.255.0
DEVICE="ens3:1"
NAME="ens3:1"
ONBOOT="yes
Systemd was spitting out the following errors:
Jun 14 01:04:19 webapps network: RTNETLINK answers: File exists
Jun 14 01:04:19 webapps network: RTNETLINK answers: File exists
Jun 14 01:04:19 webapps network: RTNETLINK answers: File exists
Jun 14 01:04:19 webapps network: RTNETLINK answers: File exists
Fix
It turns out that the DEVICE and NAME declaration needs to be assigned and specified before the networking information.
DEVICE="ens3:1"
TYPE="Ethernet"
NAME="ens3:1"
BOOTPROTO="static"
IPADDR=192.168.100.218
NETMASK=255.255.255.0
ONBOOT="yes"
centos networking