#!/bin/bash

IFACE="enp0s8"

# п.2а
nmcli con show
CON_NAME=$(nmcli -t -f NAME,DEVICE con show | awk -F: -v d="$IFACE" '$2==d{print $1}')
nmcli con mod "$CON_NAME" \
    ipv4.method manual \
    ipv4.addresses 10.100.0.2/24 \
    ipv4.gateway 10.100.0.1 \
    ipv4.dns 8.8.8.8
nmcli con up "$CON_NAME"

# п.2b
nmcli con add type dummy ifname dm0 con-name dm0 \
    ipv4.method manual ipv4.addresses 10.100.0.3/24

# п.2c
nmcli con up dm0

# п.3
ping -c 4 -I "$IFACE" 10.100.0.3
ping -c 4 -I dm0 10.100.0.2

# п.4
ip -brief link show dm0