[Firewall Issue] Is there a way to block all syn connections?

And what exactly are you reffering to by syn? I am not aware of it.
What firewall are you using?
 
jmstacey said:
And what exactly are you reffering to by syn? I am not aware of it.
What firewall are you using?
SYN_RECV via port 80.
APF & Iptables...

I already tried:
/sbin/iptables -I INPUT -p tcp --tcp-flags ALL NONE -j DROP
/sbin/iptables -I INPUT -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP
/sbin/iptables -I INPUT -p tcp --tcp-flags SYN,RST SYN,RST -j DROP
/sbin/iptables -I INPUT -p tcp --tcp-flags FIN,RST FIN,RST -j DROP
/sbin/iptables -I INPUT -p tcp --tcp-flags ACK,FIN FIN -j DROP
/sbin/iptables -I INPUT -p tcp --tcp-flags ACK,PSH PSH -j DROP
/sbin/iptables -I INPUT -p tcp --tcp-flags ACK,URG URG -j DROP
/sbin/iptables -A INPUT -p tcp --dport 80 --syn -j DROP

and some tweaks in sysctl, but it still dosnt block evrey syn connection.
 
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Have you looked up "block syn connection" (without the quotes) in google?

Jeff
 
Port scanning

We will receive SYN packet when someone do port scanning towards our machine right?

We also can block port scanning, by manipulating this matter, thise packet thing. I dont really know about it.

Can someone give me "ipfw" command to block port scanning to my machine?

Does APF works good? I'm planning to install Brute Force Detection, http://www.rfxnetworks.com/bfd.php, but it works with APF..
Can APF be installed with FreeBSD?

I'm using FreeBSD 4.11..

Thanks
 
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