Some Software-as-a-Service (SaaS)
providers publish lists of IP addresses and URLs as destination endpoints for
their SaaS applications. SaaS providers frequently update the SaaS applications
destination endpoint lists as support grows and the service expands. This
requires you to manually monitor the SaaS application endpoints for changes and
manually update your policy configuration to ensure connectivity to these
critical SaaS applications or set up an external tool to monitor and update your
EDLs.
Configure an EDL using the
EDL Hosting Service maintained by Palo
Alto Networks to ease the operational burden of maintaining an EDL for a SaaS
application. The EDL Hosting Service provides publicly available Feed URLs for
SaaS application endpoints published by the SaaS application provider.
Leveraging a Feed URL as the source in an EDL allows for dynamic enforcement of
SaaS application traffic without the need for you to host and maintain your own
EDL source.
Palo Alto Networks checks the application Feed URLs published by SaaS providers
on a daily basis and optimizes the IP address information received from SaaS
application providers in order to reduce the number of IP addresses that are
published in each EDL. This optimization includes identifying and removing
duplicate IP addresses and then aggregating the remaining IP addresses into a
smaller number of contiguous address ranges.
Microsoft updates all Microsoft 365 Feed URLs at the end of each calendar month
and provides a 30 day advanced notice prior to update. See the
official Microsoft 365 Web Services
page for more information. Additionally, the endpoints for the
Microsoft 365 Common and Office Online SaaS application are always added to
every Feed URL in the EDL Hosting Service.
Follow these steps to create an external dynamic list using the EDL Hosting
Service.
Create an External Dynamic List Using the EDL Hosting Service (Strata Cloud
Manager)
Leveraging a Feed URL as the source in an EDL allows for dynamic enforcement of SaaS
application traffic without the need for you to host and maintain your own EDL source.
Visit the
EDL Hosting Service and identify the
Feed URL for your SaaS application.
Review the
Microsoft 365 documentation for
more information which Feed URL is best for your use case. Additionally,
consider the SaaS application and location of users accessing the SaaS
application when identifying a Feed URL to. For example, if you have a
branch in Germany that only needs to access Exchange Online, select a Feed
URL from the
Service Area: Exchange Online for
Germany.
(
Best Practices) Create a certificate profile to authenticate the EDL
Hosting Service.
Download the
GlobalSign Root R1
certificate.
Convert the GlobalSign Root R1 Certificate to PEM Format.
Import the GlobalSign Root R1 certificate.
Select and Import a new
custom certificate.
Enter a descriptive Certificate
Name.
For the Certificate File, select
Browse and select the certificate
you converted in the previous step.
For the Format, select
Base64 Encoded Certificate
(PEM).
Select Save.
Create a certificate authority (CA) certificate profile.
Select and Add Profile.
Enter a descriptive Name.
For the CA Certificates,
Add the certificate you imported
in the previous step.
Select Save.
Select
Push Config.
Create an EDL using a Feed URL from the EDL Hosting Service.
Select and
Add External Dynamic
List.
Enter a descriptive
Name for the EDL.
Select the EDL
Type.
For an IP-based EDL, select IP
List.
For a URL-based EDL, select URL
List.
(
Optional) Enter a
Description for the
EDL Enter the Feed URL as the EDL
Source.
Enforce all endpoints within a specific Feed URL. Adding an
excluding a specific endpoint from a Feed URL can cause
connectivity issues to the SaaS application.
(
Best Practices) Select the
Certificate
Profile you created in the previous step.
Specify the frequency your environment should
Check for
updates to match the update frequency of the Feed
URL.
For example, if the Feed URL is updated daily by Palo Alto Networks
then configure the EDL to check for updates
Daily.
Palo Alto Networks displays the update frequency for each Feed URL in
the
EDL Hosting Service. Feed
URLs are automatically updated with any new endpoints.
Select
Save.
Enforce Policy on an External Dynamic List.
When you enforce policy on an EDL from the EDL Hosting Service where the EDL
is the source, be specific when configuring which users have access to the
SaaS application to avoid over-provisioning access to the application.
Leverage
App-ID alongside EDLs in a
security rule for additional strict enforcement of SaaS application
traffic.
Create an External Dynamic List Using the EDL Hosting Service (PAN-OS &
Panorama)
Leveraging a Feed URL as the source in an EDL allows for dynamic enforcement of SaaS
application traffic without the need for you to host and maintain your own EDL source.
Visit the
EDL Hosting Service and identify the
Feed URL for your SaaS application.
Review the
Microsoft 365 documentation for
more information which Feed URL is best for your use case. Additionally,
consider the SaaS application and location of users accessing the SaaS
application when identifying a Feed URL to. For example, if you have a
branch in Germany that only needs to access Exchange Online, select a Feed
URL from the
Service Area: Exchange Online for
Germany.
(
Best Practices) Create a certificate profile to authenticate the EDL
Hosting Service.
Download the
GlobalSign Root R1
certificate.
Convert the GlobalSign Root R1 Certificate to PEM Format.
Launch the firewall web
interface.
Import the GlobalSign Root R1 certificate.
Select and Import a new
certificate.
For Certificate Type, select
Local.
Enter a descriptive Certificate
Name.
For the Certificate File, select
Browse and select the certificate
you converted in the previous step.
For the File Format, select
Base64 Encoded Certificate
(PEM).
Click OK.
Create a certificate authority (CA) certificate profile.
Select and Add a new
certificate profile.
Enter a descriptive Name.
For the CA Certificates,
Add the certificate you imported
in the previous step.
Click OK.
Commit.
Create an EDL using a Feed URL from the EDL Hosting Service.
Select and
Add a new EDL.
Enter a descriptive
Name for the EDL.
Select the EDL
Type.
For an IP-based EDL, select IP
List.
For a URL-based EDL, select URL
List.
(
Optional) Enter a
Description for the
EDL Enter the Feed URL as the EDL
Source.
Enforce all endpoints within a specific Feed URL. Adding an
excluding a specific endpoint from a Feed URL can cause
connectivity issues to the SaaS application.
(
Best Practices) Select the
Certificate
Profile you created in the previous step.
Specify the frequency the firewall should
Check for
updates to match the update frequency of the Feed
URL.
For example, if the Feed URL is updated daily by Palo Alto Networks
then configure the EDL to check for updates
Daily.
Palo Alto Networks displays the update frequency for each Feed URL in
the
EDL Hosting Service. Feed
URLs are automatically updated with any new endpoints.
Click
Test Source URL to verify that the
firewall can access the Feed URL from the EDL Hosting Service.
Click
OK.
Enforce Policy on an External Dynamic List.
When you enforce policy on an EDL from the EDL Hosting Service where the EDL
is the source, be specific when configuring which users have access to the
SaaS application to avoid over-provisioning access to the application.
Leverage
App-ID alongside EDLs in a
security rule for additional strict enforcement of SaaS application
traffic.