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Access Control Lists (Firewall Filters)

SUMMARY Read this topic to learn about Layer 2 access control lists (Firewall filters) in the cloud-native router.

Access Control Lists (Firewall Filters)

Starting with Juniper Cloud-Native Router Release 22.2 we've included a limited firewall filter capability. You can configure the filters using the Junos OS CLI within the cloud-native router controller, using NETCONF, or the cloud-native router APIs. Starting with Juniper Cloud-Native Router Release 23.2, you can also configure firewall filters using node annotations and custom configuration template at the time of JCNR deployment. Please review the deployment guide for more details.

During deployment, the system defines and applies firewall filters to block traffic from passing directly between the router interfaces. You can dynamically define and apply more filters. Use the firewall filters to:

  • Define firewall filters for bridge family traffic.

  • Define filters based on one or more of the following fields: source MAC address, destination MAC address, or EtherType.

  • Define multiple terms within each filter.

  • Discard the traffic that matches the filter.

  • Apply filters to bridge domains.

Configuration Example

Below you can see an example of a firewall filter configuration from a cloud-native router deployment:

Note: You can configure up to 16 terms in a single firewall filter. The only then action you can configure in a firewall filter is the discard action.
After configuration, you must apply your firewall filters to a bridge domain using the set routing-instances vswitch bridge-domains bd3001 forwarding-options filter input filter1 configuration command. Then you must commit the configuration for the firewall filter to take effect.

To see how many packets matched the filter (per VLAN), you can issue the show firewall filter filter1 command on the controller CLI. For example:

In the preceding example, we applied the filter to the bridge domain bd3001. The filter has not yet matched any packets.


The following table lists some of the potential problems that you might face when you implement firewall rules or ACLs in the cloud-native router. You run most of these commands on the host server.

Table 1: L2 Firewall Filter or ACL Troubleshooting
Problem Possible Causes and Resolution Command
Firewall filters or ACLs not working gRPC connection (port 50052) to the vRouter is down. Check the gRPC connection.
netstat -antp|grep 50052
The ui-pubd process is not running. Check whether ui-pubd is running.
ps aux|grep ui-pubd
Firewall filter or ACL show commands not working The gRPC connection (port 50052) to the vRouter is down. Check the gRPC connection.
netstat -antp|grep 50052
The firewall service is not running.
ps aux|grep firewall
show log filter.log
You must run this command in the JCNR-controller (cRPD) CLI.