TP-Link TL-WR850N User Manual page 42

Chapter 4
• Firewall - A firewall protects your network from Internet attacks.
• SPI Firewall
filtering) helps to prevent cyber attacks by tracking more state per session. It
validates that the traffic passing through the session conforms to the protocol.
SPI Firewall is enabled by default.
• VPN - VPN Passthrough must be enabled if you want to allow VPN tunnels using IPSec,
PPTP or L2TP protocols to pass through the router's firewall.
• PPTP Passthrough
to-Point Protocol (PPP) to be tunneled through an IP network. If you want to allow
PPTP tunnels to pass through the router, you can keep the default (Enabled).
• L2TP Passthrough
to enable Point-to-Point sessions via the Internet on the Layer 2 level. If you
want to allow L2TP tunnels to pass through the router, you can keep the default
(Enabled).
• IPSec Passthrough
ensuring private, secure communications over Internet Protocol (IP) networks,
through the use of cryptographic security services. If you want to allow IPSec
tunnels to pass through the router, you can keep the default (Enabled).
• ALG - It is recommended to enable Application Layer Gateway (ALG) because ALG
allows customized Network Address Translation (NAT) traversal filters to be plugged
into the gateway to support address and port translation for certain application layer
"control/data" protocols such as FTP, TFTP, H323 etc.
- SPI (Stateful Packet Inspection, also known as dynamic packet
- Point-to-Point Tunneling Protocol (PPTP) allows the Point-
- Layer 2 Tunneling Protocol (L2TP) is the method used
- Internet Protocol Security (IPSec) is a suite of protocols for
Configure the Router
39