ADTRAN NetVanta 2730 Getting Started Manual Download

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Configuring Additional Interfaces

•

Basic Active/Passive Failover

—Sends traffic through the

Secondary WAN interface if the Primary WAN interface has
been marked inactive. This item has an associated

Preempt and fail back to Primary WAN when possible

checkbox. When selected, the ADTRAN security appliance
switches back to sending its traffic across the Primary
WAN interface when it resumes responding to the
ADTRAN security appliance’s checks.

•

Per Destination Round-Robin

—Load balances outgoing

traffic on a per-destination basis. This is a simple load
balancing method that allows you to utilize both links in a
basic fashion.

•

Spillover-Based

—When this setting is selected, the user

can specify when the ADTRAN security appliance starts
sending traffic through the Secondary WAN interface.
Specify the maximum allowed bandwidth on the primary
WAN interface in the

Send traffic to Secondary WAN

interface when bandwidth exceeds _ Kbps

field.

•

Percentage-Based

—When this setting is selected, you

can specify the percentages of traffic sent through the
Primary WAN and Secondary WAN interfaces, utilizing
both interfaces.
•

Use Source and Destination IP Address Binding

—

This checkbox enables you to maintain a consistent
mapping of traffic flows with a single outbound WAN
interface, regardless of the percentage of traffic
through that interface.

Click

Accept

WAN Probe Monitoring

Enabling probe monitoring on the Network > WAN Failover &
Load Balancing page instructs the ADTRAN security appliance
to perform logical checks of upstream targets to ensure that the
line is indeed usable, eliminating this potential problem, as well
as continue to do physical monitoring. Under the default probe
monitoring configuration, the appliance performs an ICMP ping
probe of both WAN ports’ default gateways. Unfortunately, this
is also not an assured means of link monitoring because
service interruption may be occurring further upstream.

To perform reliable link monitoring, you can choose ICMP or
TCP as monitoring method, and can specify up to two targets
for each WAN port. TCP is preferred because many devices on
the public Internet now actively drop or block ICMP requests. If
you specify two targets for each WAN interface, you can
logically link the two probe targets such that if either one fails
the line will go down, or that both must fail for the line to be
considered down. Using the latter method, you can configure a
sort of ‘deep check’ to see if the line is truly usable – for
instance, you could set first probe target of your ISP’s router
interface using ICMP (assuming they allow this), and then do a
secondary probe target of a DNS server on the public Internet
using TCP Port 53. With this method, if the ICMP probe of the
ISP’s router fails but the farther upstream continues to respond,
the ADTRAN security appliance assumes the link is usable and
continues to send traffic across it.