Chapter 9 Interfaces
USG20(W)-VPN Series User’s Guide
219
• PPPoE does not usually require any special configuration of the modem.
PPTP is used to set up virtual private networks (VPN) in unsecure TCP/IP environments. It sets up
two sessions.
1
The first one runs on TCP port 1723. It is used to start and manage the second one.
2
The second one uses Generic Routing Encapsulation (GRE, RFC 2890) to transfer information
between the computers.
PPTP is convenient and easy-to-use, but you have to make sure that firewalls support both PPTP
sessions.
9.11 Trunk Overview
Use trunks for WAN traffic load balancing to increase overall network throughput and reliability.
Load balancing divides traffic loads between multiple interfaces. This allows you to improve quality
of service and maximize bandwidth utilization for multiple ISP links.
Maybe you have two Internet connections with different bandwidths. You could set up a trunk that
uses spillover or weighted round robin load balancing so time-sensitive traffic (like video) usually
goes through the higher-bandwidth interface. For other traffic, you might want to use least load
first load balancing to even out the distribution of the traffic load.
Suppose ISP A has better connections to Europe while ISP B has better connections to Australia.
You could use policy routes and trunks to have traffic for your European branch office primarily use
ISP A and traffic for your Australian branch office primarily use ISP B.
Or maybe one of the USG's interfaces is connected to an ISP that is also your Voice over IP (VoIP)
service provider. You can use policy routing to send the VoIP traffic through a trunk with the
interface connected to the VoIP service provider set to active and another interface (connected to
another ISP) set to passive. This way VoIP traffic goes through the interface connected to the VoIP
service provider whenever the interface’s connection is up.
• Use the
Trunk
summary screen (
) to view the list of configured trunks
and which load balancing algorithm each trunk uses.
• Use the
Add Trunk
screen (
) to configure the member interfaces for
a trunk and the load balancing algorithm the trunk uses.
• Use the
Add System Default
screen (
) to configure the load
balancing algorithm for the system default trunk.
9.11.1 What You Need to Know
• Add WAN interfaces to trunks to have multiple connections share the traffic load.
• If one WAN interface’s connection goes down, the USG sends traffic through another member of
the trunk.
• For example, you connect one WAN interface to one ISP and connect a second WAN interface to
a second ISP. The USG balances the WAN traffic load between the connections. If one interface's
connection goes down, the USG can automatically send its traffic through another interface.
Summary of Contents for ZyWall USG20-VPN
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