# Traffic Permissions
This policy provides access control rules to define the traffic that is allowed within the Mesh.
Traffic permissions requires Mutual TLS enabled on the
Mesh. Mutual TLS is required for Kuma to validate the service identity with data plane proxy certificates. If Mutual TLS is disabled, Kuma allows all service traffic.
TrafficPermission policy that Kuma creates when you install allows all communication between all services in the new
Mesh. Make sure to configure your policies to allow appropriate access to each of the services in your mesh.
As of version 1.2.0, traffic permissions support the
ExternalService resource. This lets you configure access control for traffic to services outside the mesh.
To specify which source services can consume which destination services, provide the appropriate values for
kuma.io/service. This value is required for sources and destinations.
Match all: You can match any value of a tag by using
* -- for example, like
You can use any Tag with the
destinations selectors. This approach supports fine-grained access control that lets you define the right levels of security for your services.
# Access to External Services
TrafficPermission policy can also be used to restrict traffic to services outside the mesh.
These settings lock down traffic to and from the mesh, which means that requests to any unknown destination are not allowed. The mesh can't rely on mTLS, because there is no data plane proxy on the destination side.
First, define the
ExternalService for a service that is not in the mesh.
Then apply the
TrafficPermission policy. In the destination section, specify all the tags defined in
For example, to enable the traffic from the data plane proxies of service
backend to the new
ExternalService follows the same rules for matching policies as any other service in the mesh -- Kuma selects the most specific
TrafficPermission for every