Tanzu Platform for Cloud Foundry 4.0

Routing Network Communications

Last Updated March 13, 2025

The following tables show the internal network communication paths of the routing subsystem with other VMware Tanzu Application Service for VMs (TAS for VMs) components.

HTTP routing

The following table lists network communication paths for HTTP routing:

Source VMDestination VMPortTransport Layer ProtocolApp Layer ProtocolSecurity and Authentication
diego_cell (local Route Emitter)nats4222TCPNATSBasic authentication
Load balancerrouter (Gorouter)80TCPHTTPNone
Load balancerrouter (Gorouter)443TCPHTTPSTLS
router (Gorouter)nats4222TCPNATSBasic authentication
router (Gorouter)System componentsVariesTCPVariesNone
router (Gorouter)App containersVariesTCPVariesOptional TLS
Load balancerrouter (Gorouter)80TCPHTTPNone
Load balancerrouter (Gorouter)443TCPHTTPSTLS

TCP routing (optional)

The following table lists network communication paths for TCP routing:

Source VMDestination VMPortTransport Layer ProtocolApp Layer ProtocolSecurity and Authentication
cloud_controllercloud_controller (Routing API)*443TCPHTTPSTLS and OAuth 2.0
cloud_controller (Routing API)diego_database (Locket)8891TCPHTTPSMutual TLS
cloud_controller (Routing API)mysql_proxy3306TCPMySQLMySQL authentication**
cloud_controller (Routing API)uaa8443TCPHTTPSTLS
diego_brain (global TCP Emitter)cloud_controller (Routing API)3000TCPHTTPOAuth 2.0
diego_brain (global TCP Emitter)cloud_controller (Routing API)3001TCPHTTPSMutual TLS
diego_brain (global TCP Emitter)uaa8443TCPHTTPSTLS
diego_cell (local Route Emitter)cloud_controller (Routing API)3000TCPHTTPOAuth 2.0
diego_cell (local Route Emitter)cloud_controller (Routing API)3001TCPHTTPSMutual TLS
diego_cell (local Route Emitter)uaa8443TCPHTTPSTLS
Load balancertcp_router1024-65535TCPTCPNone
router (Gorouter)cloud_controller (Routing API)3000TCPHTTPOAuth 2.0
router (Gorouter)cloud_controller (Routing API)3001TCPHTTPSMutual TLS
router (Gorouter)uaa8443TCPHTTPSTLS
tcp_routercloud_controller (Routing API)3000TCPHTTPOAuth 2.0
tcp_routercloud_controller (Routing API)3001TCPHTTPSMutual TLS
tcp_routeruaa8443TCPHTTPSTLS

* This communication happens through a load balancer and a Gorouter. Requests are received by Routing API on port 3000 or 3001. You can use Routing API Endpoint Protocol toggle when configuring TAS for VMs tile for enabling HTTPS only

You can use this port range to configure the port in the TAS for VMs tile.

** MySQL authentication uses the MySQL native password method.

Service Mesh (optional)

The following table lists network communication paths for service mesh:

Source VMDestination VMPortTransport Layer ProtocolApp Layer ProtocolSecurity and Authentication
cloud_controller (cloud_controller_ng)istio_control (Copilot)9001TCPGRPCMutual TLS
istio_control (Copilot)diego_database (BBS)8889TCPHTTPMutual TLS
istio_control (Pilot-Discovery)istio_control (Copilot)9009TCPGRPCMutual TLS
istio_router (Envoy)App containersVariesTCPHTTP/HTTPSOptional TLS
istio_router (Envoy)istio_control (Pilot-Discovery)15010TCPGRPCNone
Load balanceristio_router (Envoy)80TCPHTTPNone
Load balanceristio_router (Envoy)443TCPHTTPSTLS
Load balancer (health check)istio_router (Envoy)8002TCPHTTPNone
route_syncer (CC Route Syncer)istio_control (Copilot)9001TCPGRPCMutual TLS
route_syncer (CC Route Syncer)mysql_proxy*3306TCPMySQLMySQL authentication*
N/A (admin)istio_router (Envoy)8001TCPHTTPNone
N/A (for Envoy secure GRPC communication)istio_control (Pilot-Discovery)15012TCPGRPCMutual TLS
N/A (for HTTP discovery service)istio_control (Pilot-Discovery)8080TCPHTTPNone
N/A (for Pilot’s self-monitoring)istio_control (Pilot-Discovery)9093TCPHTTPNone

*Applies only to deployments where internal MySQL is selected as the database.

BOSH DNS communications

By default, TAS for VMs components and app containers look up services using the BOSH DNS service discovery mechanism. To support this lookup, BOSH Director co-locates a BOSH DNS server on every deployed VM. For more information, see BOSH DNS network communications.