QNX Developer Support
Provide IP filter services
mount -Ttcpip lsm-ipfilter.so
The lsm-ipfilter-v4.so and lsm-ipfilter-v6.so shared objects are the managers that handles IP filtering and NAT (Network Address Translation) services. The npm-tcpip.so shared object can load these modules. You need to load this manager to enable filtering and NAT functionality.
IP filtering allows your host to act as a firewall, or you can provide firewall services on your host. NAT allows multiple hosts on a subnet to share a common IP address. Configuration files are used to set filtering and NAT rules. For more details, see /etc/ipf.conf and /etc/ipnat.conf.
"Setting up a firewall" in the Securing Your System chapter of the Neutrino User's Guide