Port/IP address Redirection is one of best feature of CSF ConfigServer Security Firewall.
With this feature we can redirect any/all ports or IP address to alternative ports/IP addresses.
Below are requirements for Port/IP address Redirection feature :
nat tables
ipt_DNAT iptables module
ipt_SNAT iptables module
ipt_REDIRECT iptables module
The following are the allowed redirection formats :
# DNAT (redirect from one IP address to a different one):
IPx|*|IPy|*|tcp/udp – To IPx redirects to IPy
IPx|portA|IPy|portB|tcp/udp – To IPx to portA redirects to IPy portB
# DNAT examples:
192.168.254.62|*|10.0.0.1|*|tcp
192.168.254.62|666|10.0.0.1|25|tcp
# REDIRECT (redirect from port to a different one):
IPx|portA|*|portB|tcp/udp – To IPx to portA redirects to portB
*|portA|*|portB|tcp/udp – To portA redirects to portB
# REDIRECT examples:
*|666|*|25|tcp
192.168.254.60|666|*|25|tcp
192.168.254.4|666|*|25|tcp