This Bash script flushes all IP addresses from a predefined list of network interfaces, then presents a menu allowing the user to configure one of several predefined IPv4/IPv6 address and route setups (while unsetting proxy variables) before exiting.

Internet_exit_selection.sh

#!/bin/bash

# List of interfaces
interfaces=("enp5s0" "enp6s0" "enp7s0")

# Loop through each interface and flush IP addresses
for iface in "${interfaces[@]}"; do
    echo "Flushing IP addresses from $iface..."
    ip addr flush dev "$iface"
done

echo "All specified interfaces have been flushed."


# Define the menu options as an array
options=("instance1" "instance2" "instance3" "Exit")

# Set the prompt for the select statement
PS3="Please choose an option: "

# Loop indefinitely until the user chooses to exit
select choice in "${options[@]}"; do
    case $choice in
        "instance1")
            ip link set enp5s0 up && \
            ip -4 addr add 192.168.1.63/31 dev enp5s0 && \
            ip -4 route add 0.0.0.0/0 via 192.168.1.62 dev enp5s0
            ip -6 addr add 2001:db8:742:c01:151:8888:0:a/96 dev enp5s0
            ip -6 route add ::/0 via 2001:db8:742:c01:151:8888:0:1 dev enp5s0
            echo ""
            ip link show enp5s0
            ip -4 addr show enp5s0
            ip -6 addr show enp5s0
            ip -4 route show
            ip -6 route show
            unset http_proxy
            unset https_proxy
            break
            ;;
        "instance2")
            ip link set enp7s0 up && \
            ip -4 addr add 192.168.1.65/31 dev enp6s0 && \
            ip -4 route add 0.0.0.0/0 via 192.168.1.64 dev enp6s0
            ip -6 addr add 2001:db8:742:c01:152:8888:0:a/96 dev enp6s0
            ip -6 route add ::/0 via 2001:db8:742:c01:152:8888:0:1 dev enp6s0
            echo ""
            ip link show enp6s0
            ip -4 addr show enp6s0
            ip -6 addr show enp6s0
            ip -4 route show
            ip -6 route show
            unset http_proxy
            unset https_proxy
            break
            ;;
        "instance3")
            ip link set enp6s0 up && \
            ip -4 addr add 192.168.1.67/31 dev enp7s0 && \
            ip -4 route add 0.0.0.0/0 via 192.168.1.66 dev enp7s0
            ip -6 addr add 2001:db8:742:c01:153:8888:0:a/96 dev enp7s0
            ip -6 route add ::/0 via 2001:db8:742:c01:153:8888:0:1 dev enp7s0
            echo ""
            ip link show enp7s0
            ip -4 addr show enp7s0
            ip -6 addr show enp7s0
            ip -4 route show
            ip -6 route show
            unset http_proxy
            unset https_proxy
            break
            ;;
        "Exit")
            echo "Exiting menu. Goodbye!"
            break # Exit the select loop
            ;;
        *)
            echo "Invalid option. Please choose a number from the menu."
            ;;
    esac
    echo # Add a blank line for readability
done