ufw (Uncomplicated Firewall):sudo ufw allow 22/tcp
sudo ufw allow 80/tcp
sudo ufw deny 23/tcp
sudo ufw enable
sudo ufw status numbered
22 (SSH).80 (HTTP).23 (Telnet).telnet IP_DA_VM 23
curl http://IP_DA_VM
nmap -p 22,23,80 IP_DA_VM
telnet, curl e nmap de outra máquina ou container para testar:tcpdump (opcional): sudo tcpdump -i any port 23
sudo less /var/log/ufw.log
from collections import Counter
with open("/var/log/ufw.log") as f:
ips = [line.split()[8] for line in f if "BLOCK" in line]
for ip, count in Counter(ips).most_common():
print(f"{ip} → {count} tentativas bloqueadas")
ufw ativascurl, telnet e nmap