Service Routes
Table of Contents
Service Routes
The firewall uses the management (MGT) interface
by default to access external services, such as DNS servers, external
authentication servers, Palo Alto Networks services such as software,
URL updates, licenses and AutoFocus. An alternative to using the
MGT interface is to configure a data port (a regular interface)
to access these services. The path from the interface to the service
on a server is known as a service route. The service
packets exit the firewall on the port assigned for the external
service and the server sends its response to the configured source
interface and source IP address.
When set to default
settings, certain services (such as External Dynamic Lists and URL
updates) use service route settings that are inherited by a parent
service (in this case, Palo Alto Networks Services) if it is explicitly
configured with an interface. If the defaults are not used, Palo
Alto Networks recommends configuring each of the services that you
use with an interface to ensure that the proper service route is used.
You
can configure service routes globally for the firewall (shown in
the following task) or Customize
Service Routes for a Virtual System on a firewall enabled
for multiple virtual systems so that you have the flexibility to
use interfaces associated with a virtual system. Any virtual system
that does not have a service route configured for a particular service
inherits the interface and IP address that are set globally for
that service.
For firewalls in a high availability (HA)
configuration, the service route configuration is synchronized across the HA peers.
For firewalls in an active/passive high
availability (HA), the service route you configured to leverage an
external service or for log forwarding sees activity only on the
active HA peer while the
passive HA peer sees no activity if you configured
an Ethernet interface as the Source Interface. For example,
you configure a service route with Ethernet 1/3 as the source interface to forward
logs to Cortex Data Lake. In this scenario, all logs are forwarded from the
active HA peer but no logs, including the system
and configuration logs, are forwarded from the passive
HA peer. However, if you configure the MGT interface as the service route
Source Interface, activity occurs on both the
active and passive HA
peers.
The following procedure enables you to change
the interface the firewall uses to send requests to external services.
- Customize service routes.
- Select (omit
Global on a firewall without multiple virtual system capability),
and in the Services Features section, click Service Route
Configuration.
![]()
- Select Customize and
do one of the following to create a service route:
- For a predefined service:
- Select IPv4 or IPv6 and click the link for the service for which you want customize the service route.To easily use the same source address for multiple services, select the checkbox for the services, click Set Selected Routes, and proceed to the next step.
- To limit the list for Source Address, select a Source Interface; then select a Source Address (from that interface) as the service route. An Address Object can also be referenced as a Source Address if it is already configured on the selected interface. Selecting Any Source Interface makes all IP addresses on all interfaces available in the Source Address list from which you select an address. Selecting Use default causes the firewall to use the management interface for the service route, unless the packet destination IP address matches the configured Destination IP address, in which case the source IP address is set to the Source Address configured for the Destination. Selecting MGT causes the firewall to use the MGT interface for the service route, regardless of any destination service route.The Service Route Source Address does not inherit configuration changes from the referenced interface and vice versa. Modification of an Interface IP Address to a different IP address or Address Object will not update a corresponding Service Route Source Address. This may lead to commit failure and require you to update the Service Route(s) to a valid Source Address value.
- Click OK to save the setting.
- Repeat this step if you want to specify both an IPv4 and IPv6 address for a service.
- For a destination service route:
- Select Destination and Add a Destination IP address. In this case, if a packet arrives with a destination IP address that matches this configured Destination address, then the source IP address of the packet will be set to the Source Address configured in the next step.
- To limit the list for Source Address, select a Source Interface; then select a Source Address (from that interface) as the service route. Selecting Any Source Interface makes all IP addresses on all interfaces available in the Source Address list from which you select an address. Selecting MGT causes the firewall to use the MGT interface for the service route.
- Click OK to save the setting.
- Repeat the prior steps for each service route you want to customize.
- Click OK to save the service route configuration.
- Select (omit
Global on a firewall without multiple virtual system capability),
and in the Services Features section, click Service Route
Configuration.
- Commit.Click Commit.
