iptables doesn't seem to be blocking IPs I ban
As a test, I started a TorBrowser, got its IP, and banned it via this command on my VPS:
sudo iptables -A INPUT -s <IP address> -j DROP
I'm still able to surf pages hosted by my server from the TorBrowser. I've even double checked the HTTP access.log to make sure the IP is what I banned, and it is. What am I missing?
My iptables file that gets read in upon boot (via iptables-restore)
# Allow all loopback (lo0) traffic and drop all traffic to 127/8 that doesn't use lo0
-A INPUT -i lo -j ACCEPT
-A INPUT -d 127.0.0.0/8 -j REJECT
# IP bans
-A INPUT -s 42.121.24.80 -j DROP
-A INPUT -s 121.196.43.157 -j DROP
-A INPUT -s 192.30.85.135 -j DROP
-A INPUT -s 94.102.53.175 -j DROP
# Accept all established inbound connections
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
# Allow all outbound traffic - you can modify this to only allow certain traffic
-A OUTPUT -j ACCEPT
# Allow HTTP and HTTPS connections from anywhere (the normal ports for websites and SSL).
-A INPUT -p tcp --dport 80 -j ACCEPT
-A INPUT -p tcp --dport 443 -j ACCEPT
-A INPUT -p tcp --dport 8080 -j ACCEPT
# Mail
-A INPUT -p tcp --dport 993 -j ACCEPT
-A INPUT -p tcp --dport 465 -j ACCEPT
-A INPUT -p tcp --dport 587 -j ACCEPT
-A INPUT -p tcp --dport 25 -j ACCEPT
# Minecraft
-A INPUT -p tcp --dport 25565 -j ACCEPT
# Allow SSH connections
#
# The -dport number should be the same port number you set in sshd_config
#
-A INPUT -p tcp -m state --state NEW --dport 22 -j ACCEPT
# Allow ping
-A INPUT -p icmp -j ACCEPT
# Log iptables denied calls
-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7
# Drop all other inbound - default deny unless explicitly allowed policy
-A INPUT -j DROP
-A FORWARD -j DROP
COMMIT
And iptables -L output:
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere
REJECT all -- anywhere 127.0.0.0/8 reject-with icmp-port-unreachable
DROP all -- out524-80.mail.aliyun.com anywhere
DROP all -- ip196.hichina.com anywhere
DROP all -- 192.30.85.135-IP-Static-VISPERAD.COM anywhere
DROP all -- tor-exit-nl1.privacyfoundation.dk anywhere
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp dpt:http
ACCEPT tcp -- anywhere anywhere tcp dpt:https
ACCEPT tcp -- anywhere anywhere tcp dpt:http-alt
ACCEPT tcp -- anywhere anywhere tcp dpt:imaps
ACCEPT tcp -- anywhere anywhere tcp dpt:ssmtp
ACCEPT tcp -- anywhere anywhere tcp dpt:submission
ACCEPT tcp -- anywhere anywhere tcp dpt:smtp
ACCEPT tcp -- anywhere anywhere tcp dpt:25565
ACCEPT tcp -- anywhere anywhere state NEW tcp dpt:ssh
ACCEPT icmp -- anywhere anywhere
LOG all -- anywhere anywhere limit: avg 5/min burst 5 LOG level debug prefix "iptables denied: "
DROP all -- anywhere anywhere
Chain FORWARD (policy ACCEPT)
target prot opt source destination
DROP all -- anywhere anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere
Solution 1:
dmourati asked for iptables -L INPUT for a reason, aka your current rules.
Before testing the torbrowser, you had the posted rules (or similar).
Now on the middle of it :
-A INPUT -p tcp --dport 80 -j ACCEPT
After that you executed
iptables -A INPUT -s <IP address> -j DROP
So your rule ended up AFTER you accepted all port 80 traffic, thus nothing to DROP since was already accepted.
You should have added the rule with
iptables -I INPUT -s <IP address> -j DROP
Solution 2:
If you want to give priority to the drop command you need to insert (-I) it before the append (-A) command that allows port 80.
Order matters, try:
sudo iptables -I INPUT -s <IP address> -j DROP