L2Tp/Pptp - Zoom Cable Modem/Router User Manual

Phase 2 DH Group
Replay Detection
NetBIOS Broadcast
Forwarding
Dead Peer Detection
Manual Encryption
Key
Manual
Authentication Key
Inbound SPI
Outbound SPI

L2TP/PPTP

The L2TP/PPTP page allows you to configure server and security settings. The L2TP
(Layer 2 Tunneling Protocol) and PPTP (Point-to-Point Tunneling Protocol) both allow
PPP frames to be tunneled through the network. PPTP is a Microsoft proprietary
protocol, which is very similar to L2TP.
To access the L2TP/PPTP page:
1
Click VPN in the menu bar.
2
Then click the L2TP/PPTP submenu.
Figure 36 shows an example of the menu and Table 32 describes the items you can
select.
Select DHx after enabling PFS.
Select Enable to enable replay detection. As VPN setup is
processing intensive, the system is vulnerable to Denial of
Service (DOS) attacks. The IPSec receiver can detect and
reject old or duplicate packets to protect against replay attacks.
Select Enable to send NetBIOS (Network Basic Input/Output
System) packets through the VPN connection. NetBIOS
packets are TCP or UDP packets that enable a computer to find
other computers. It may sometimes be necessary to allow
NetBIOS packets to pass through VPN tunnels in order to allow
local computers to find computers on the remote network and
vice versa.
Select Enable to force the Cable Modem/Router to periodically
detect if the remote IPSec Cable Modem/Router is available or
not.
If Manual mode is selected in the Key Management field, enter a
16 hexadecimal digits manual encryption key for encryption.
Enter a 32 hexadecimal digit unique authentication key to be
used by IPSec.
Enter a unique SPI (Security Parameter Index) for inbound SPI.
Enter a unique SPI (Security Parameter Index) for outbound
SPI.
106