Iptables and SYN-FLOOD attack
I've 2 problem with my new network infrastructure (I think!)
I show you a basic plan of my network.
Sometimes I lost my internet connection...
I can ping outside but webpage didn't display and no mail reception on client...
I've to restart the VPN router to make up the connection.
When the VPN router was restared, it sending me an email with information that it has been attack since my internal 192.168.1.1 ip address!
I've this POSTROUTING rules on my firewall
iptables -t nat -A POSTROUTING -o $I_RT -j MASQUERADE #I_RT is eth0 with 192.168.1.1 address
I don't know how to resolve this problem. I had some syn-flood attack prevent but they didn't work...
I drop all before allow my rules one by one.
I allow my script to forward client request to http, https, pop, smtp and it's work fine.
But I can't give access on internet since my firewall. I try many setting with INPUT and OUTPUT rules but nothings work...
Have you an idea for a good configuration to allow my firewall to access on web?
Thanks for your help!