I did an nmap against myself, in which (with wireshark) I discovered that if nmap sends a TCP ACK out to my router, my router will automatically respond with a TCP RST. Is there anyway to stop the router from sending an RST for a connection that doesn't exist? I already use:
permit tcp any any established
deny ip any any log
But that doesn't seem to work. Any advice would be appreciated.
Essentially what I'm looking to do it to Block TCP reset (RST) on closed TCP ports to prevent TCP port scanning.
Thanks.