iptables TCP Rules

Roberto Nervo

1/2/23, 3:10 AM

iptables -t raw -F
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Mozil" --algo kmp --to 65535 -m tcp --dport 1000   # You can change the port here
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Saf" --algo kmp --to 65535 -m tcp --dport 1000
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Edge" --algo kmp --to 65535 -m tcp --dport 1000
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Oper" --algo kmp --to 65535 -m tcp --dport 1000
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Chrom" --algo kmp --to 65535 -m tcp --dport 1000
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Gecko" --algo kmp --to 65535 -m tcp --dport 1000
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Andr" --algo kmp --to 65535 -m tcp --dport 1000
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "exch" --algo kmp --to 65535 -m tcp --dport 1000
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Fire" --algo kmp --to 65535 -m tcp --dport 1000
iptables -t raw -I PREROUTING -j DROP -p tcp -m string --string "Wind" --algo kmp --to 65535 -m tcp --dport 1000

If I try to access to http://127.0.0.1:1000/ it refuses the connection, but if I try https://127.0.0.1:1000 I could access, why? Thx by the way!

It's a Application Server being attacked with DDoS on layer 7. I do not have the src of application so there is no solution for blocking on iptables? What if I block the port 443 with same rules?

1 + 0

networking

iptables

Score:3

Server

parkamark

1/2/23, 4:05 AM

Because HTTP is plain text and HTTPS in encrypted.

That aside, I would seriously suggest not using this method for blocking specific user agents - it should be done within the web server itself.

0 + 0

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: iptables TCP Rules

TH: กฎ TCP ของ iptables

RO: Reguli TCP iptables

RU: TCP-правила iptables

VI: Quy tắc TCP của iptables

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