Check to see if a target is using a load balancing solution with the
lbd(load balancing detector) command.
To determine if the target is behind a web application firewall (WAF), use the
It may be needed to encode some attack tools to try to trick antivirus software into not seeing the code as being harmful.
To detect what ports a firewall is forwarding on to a target, use the
firewalkcommand. Is also available for nmap as firewalk.nse script.