How to assign an additional/alias IP addresses to a network card (NIC)?

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Hello folks,
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 ifup ens192\:1.

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 ifup|ifdown, ip or nmcli.

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.

Best regards,
Joerg

JK

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