NETGEAR UTM5-100NAS, UTM50-100NAS manual VPN Pass through, L2TP

ProSecure Unified Threat Management (UTM) Appliance Reference Manual

Table 5-4. Attack Checks Settings (continued)

Setting	Description (or Subfield and Description)
LAN Security Checks.
Block UDP flood	Select the Block UDP flood checkbox to prevent the UTM from accepting more
	than 20 simultaneous, active UDP connections from a single device on the LAN.
	By default, the Block UDP flood checkbox is deselected.
	A UDP flood is a form of denial of service attack that can be initiated when one
	device sends a large number of UDP packets to random ports on a remote host.
	As a result, the distant host does the following:
	1. Check for the application listening at that port.
	2. See that no application is listening at that port.
	3. Reply with an ICMP Destination Unreachable packet.
	When the victimized system is flooded, it is forced to send many ICMP packets,
	eventually making it unreachable by other clients. The attacker might also spoof
	the IP address of the UDP packets, ensuring that the excessive ICMP return
	packets do not reach him, thus making the attacker’s network location
	anonymous.
Disable Ping Reply	Select the Disable Ping Reply on LAN Ports checkbox to prevent the UTM
on LAN Ports	from responding to a ping on a LAN port. A ping can be used as a diagnostic
	tool. Keep this checkbox deselected unless you have a specific reason to
	prevent the UTM from responding to a ping on a LAN port.
VPN Pass through
IPSec	When the UTM functions in NAT mode, all packets going to the remote VPN
PPTP	gateway are first filtered through NAT and then encrypted per the VPN policy.
L2TP	For example, if a VPN client or gateway on the LAN side of the UTM wants to
	connect to another VPN endpoint on the WAN side (placing the UTM between
	two VPN endpoints), encrypted packets are sent to the UTM. Because the UTM
	filters the encrypted packets through NAT, the packets become invalid unless
	you enable the VPN Pass through feature.
	To enable the VPN tunnel to pass the VPN traffic without any filtering, select any
	or all of the following checkboxes:
	• IPSec. Disables NAT filtering for IPSec tunnels.
	• PPTP. Disables NAT filtering for PPTP tunnels.
	• L2TP. Disables NAT filtering for L2TP tunnels.
	By default, all three checkboxes are selected.

4.Click Apply to save your settings.

Firewall Protection 5-29

v1.0, January 2010