I'm looking for best practice to assign and manage an additional/alias IP addresses to a network card (NIC) in RHEL 7 and RHEL 8.
Most of my network configurations for a host with a single NIC looks something like this:
# cat /etc/sysconfig/network-scripts/ifcfg-ens192 TYPE=Ethernet BOOTPROTO=none DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_PEERDNS=yes IPV6_PEERROUTES=yes IPV6_FAILURE_FATAL=no IPV6_PRIVACY=no NAME=ens192 DEVICE=ens192 ONBOOT=yes DNS1=192.168.0.1 DNS2=192.168.0.2 PEERDNS=no DOMAIN="foo.example.com example.com" IPADDR=192.168.3.56 PREFIX=24 GATEWAY=192.168.3.1
Today when I have to add an additional IP address to this NIC I would create a new file called ifcfg-ens192:1 with the follwoing content:
# cat /etc/sysconfig/network-scripts/ifcfg-ens192\:1 DEVICE=ens192:1 ONPARENT=on IPADDR=192.168.3.8 PREFIX=24
Afterwards I restart the network service via
systemctl restart network to activate the new (virtual) interface. The new interface is active imediatly. How could I prevent this? The new IP should stay inactive until I enable it via
Besides that, what do you suggest is the recommend way for RHEL 7 and RHEL 8 to bring up and down (virtual) interfaces? I would like to know how to control which IP is UP or DOWN and I'm not sure wether to choose
When the additional/virtual interface is down, it is not shown in the output of
ifconfig -a and
ip a. How could I get a view of all virtual interfaces in status DOWN?
I'm looking forward reading your suggestions.