SMC Networks SMC Barricade Plus SMCBR18VPN - Manual (Page 34)

7.8.5 | Advanced
In this section you can enable/disable Stateful Packet Inspection (SPI), Discard Ping from WAN,
and PPTP and IPSec VPN Passthrough types.
When Discard Ping From WAN is enabled, computers on the Internet will not get a reply back
from the VPN Broadband Router when it is being “ping”ed. This may help to increase security.
When SPI is enabled, the router will extensively record specific packet information passed
through the router such as IP address, port address, ACK, and so on. The router will also check
every incoming packet to detect its validity.
7.8.6 | DMZ
If you have a local client PC that cannot run an Internet application properly from behind the
NAT firewall, then you can open the client up to unrestricted two-way Internet access by defining
a Virtual DMZ Host.