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Prisma SD-WAN Administrator’s Guide

Configure Application Reachability Probes

Table of Contents

Configure Application Reachability Probes

Learn more about the

Prisma SD-WAN

application reachability probes.

Configure application probes to check an application's reachability for a given path for an ION device. Application probes are initiated on detection of an unreachable prefix for an application. You may configure application reachability probes on any valid Layer 3 LAN interface.

Prisma SD-WAN

supports dynamic probing for TCP applications when 3-way handshake failures are detected. The ION device generates these dynamic probes to verify that a destination service is actually up or down on that path. If verified as down, the ION device avoids sending additional user requests for the service down the specific path while continuing to generate synthetic probes to detect any change in service reachability.

Starting with Release 6.3.2,

Prisma SD-WAN

supports probing for UDP DNS traffic. The application probes handle DNS probe requests and start a DNS probe on the destination on receiving a DNS probe request. If the DNS server responds to the request, irrespective of whether it responds with the requested domain name, the ION device treats the probe as successful. If the DNS server does not respond, the application probe notifies the flow controller to change the path.

When the probe detects that the DNS server is unreachable, the ION device continues probing once every minute for the first three probes and then once every 5 minutes. If the probe is successful again, the probe notifies the flow controller to use the path again.

You can view the health of the DNS traffic under

Monitor

Activity

App Health

Application probe is enabled by default for all ION devices, except for ION 1000. The controller port generates the application probes if you do not configure any LAN ports for generating application probes.

For the ION 1000 device, you must configure a LAN port for the application probe. If not, the controller generates an alarm. You can choose to exclude specific circuits and circuit categories from being used for checking the reachability of an application on a given path. Refer Configure Device Initiated Connections.

Select

Workflows

Devices

Claimed Devices

, select the device you want to configure.

Select

Interfaces

and a port for configuring application reachability probes.

Select

LAN

in the

For Use this Port

option.

Once an interface is designated as the application probe interface,

Use This Port For

cannot be changed from

LAN

and

Admin Up

for the interface has to be

Yes

Toggle

Yes

for

Application Reachability Probe Source Interface

Select

Static

DHCP

for

Configuration

Retain the default values for the other fields, and

Save Port

View and update the application reachability probe configuration from the

Basic Info

tab.

Toggle

Yes

for

Application Reachability Probe Source Interface

Select a port from the

Source Interface

drop-down.

The ports which have

Use This Port For

set to

LAN

appear in the drop-down.

Select

None

for

Source Interface

to use the controller port as the source interface for generating application probes.

Configure a Layer 3 LAN Interface

Configure a Secondary IP Address

Prisma SD-WAN Administrator’s Guide

Configure Application Reachability Probes

Configure Application Reachability Probes

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