Certain countries have lots (around 10000) of IP address ranges
(US,GB,DE,...). The current linear search is really bad:
No firewall:
3000 packets transmitted, 3000 received, 0% packet loss, time 1992ms
Testing against the countries with top 50 IP ranges:
3000 packets transmitted, 3000 received, 0% packet loss, time 8998ms
With binary search:
3000 packets transmitted, 3000 received, 0% packet loss, time 2358ms