Parts
The parts of a zone …
Predefined services
A service is a combination of port and/or protocol entries. Optionally netfilter helper modules can be added and also a IPv4 and IPv6 destination address.
Ports, source ports and protocols
Definition of tcp or udp ports, where ports can be a single port or a port range.
ICMP blocks
Selected Internet Control Message Protocol (ICMP) messages. These messages are either information requests or created as a reply to information requests or in error conditions.
Masquerading
The addresses of a private network are mapped to and hidden behind a public IP address. This is a form of address translation.
Forward ports
A port is either mapped to another port and/or to another host.