ipexclude.sh

#!/bin/bash
set -euo pipefail

exclude_networks=("1.2.3.4" "1.2.3.0/24")

for net in "${exclude_networks[@]}"; do
    if sudo ip route del "$net" 2>/dev/null; then
        echo "Deleted existing route for $net"
    fi
done

mapfile -t interfaces < <(ip -o link show up | awk -F': ' '{print $2}' | grep -v '^lo$')

selected_iface=""
for iface in "${interfaces[@]}"; do
    metric=$(ip route show dev "$iface" | awk '/metric/ {print $NF; exit}')
    
    if [[ "$metric" =~ ^[0-9]+$ ]] && (( metric >= 100 )); then
        gateway=$(ip route show default dev "$iface" | awk '/default/ {print $3; exit}')
        
        if [[ -n "$gateway" ]]; then
            echo "Using interface: $iface (metric: $metric, gateway: $gateway)"
            for net in "${exclude_networks[@]}"; do
                echo "Adding route for $net via gateway $gateway on interface $iface"
                sudo ip route add "$net" via "$gateway" dev "$iface"
            done
            selected_iface="$iface"
            break
        fi
    fi
done

if [[ -z "$selected_iface" ]]; then
    echo "No suitable interface found with metric >= 100 and a default gateway."
fi