protocol 'UDP' is unsupported

[mayunhao]

For Higress v2.2.3 + Gateway API 1.4.0, it shows "protocol 'UDP' is unsupported". Does this version actually support UDP?

apiVersion: v1
items:

• apiVersion: gateway.networking.k8s.io/v1
  kind: Gateway
  metadata:
  creationTimestamp: "2026-07-02T09:28:46Z"
  generation: 5
  labels:
  app.kubernetes.io/part-of: higress-gateway-api
  kubernetes.customized/cluster_component_higress: higress-gateway-api
  name: higress-gateway
  namespace: higress-system
  resourceVersion: "24652725"
  uid: 18eec768-591d-469c-9444-a4a29f7ba940
  spec:
  gatewayClassName: higress
  listeners:
  • allowedRoutes:
    kinds:
    • group: gateway.networking.k8s.io
      kind: HTTPRoute
    • group: gateway.networking.k8s.io
      kind: GRPCRoute
      namespaces:
      from: Same
      name: http
      port: 80
      protocol: HTTP
  • allowedRoutes:
    namespaces:
    from: Selector
    selector:
    matchLabels:
    kubernetes.io/metadata.name: test
    hostname: nginx.boc.cn
    name: tomcat-tls
    port: 443
    protocol: HTTPS
    tls:
    certificateRefs:
    • group: ""
      kind: Secret
      name: https-cert
      mode: Terminate
  • allowedRoutes:
    kinds:
    • group: gateway.networking.k8s.io
      kind: UDPRoute
      namespaces:
      from: Selector
      selector:
      matchLabels:
      kubernetes.io/metadata.name: test
      name: udp-5300
      port: 5300
      protocol: UDP
      status:
      addresses:
  • type: Hostname
    value: higress-gateway.higress-system.svc.cluster.local
    conditions:
  • lastTransitionTime: "2026-07-02T09:28:47Z"
    message: Resource accepted
    observedGeneration: 5
    reason: Accepted
    status: "True"
    type: Accepted
  • lastTransitionTime: "2026-07-05T10:27:30Z"
    message: Resource programmed, assigned to service(s) higress-gateway.higress-system.svc.cluster.local:443,
    higress-gateway.higress-system.svc.cluster.local:5300, and higress-gateway.higress-system.svc.cluster.local:80
    observedGeneration: 5
    reason: Programmed
    status: "True"
    type: Programmed
    listeners:
  • attachedRoutes: 0
    conditions:
    • lastTransitionTime: "2026-07-05T10:27:30Z"
      message: protocol "UDP" is unsupported
      observedGeneration: 5
      reason: UnsupportedProtocol
      status: "False"
      type: Accepted
    • lastTransitionTime: "2026-07-05T10:27:30Z"
      message: No errors found
      observedGeneration: 5
      reason: NoConflicts
      status: "False"
      type: Conflicted
    • lastTransitionTime: "2026-07-05T10:27:30Z"
      message: No errors found
      observedGeneration: 5
      reason: Programmed
      status: "True"
      type: Programmed
    • lastTransitionTime: "2026-07-05T10:27:30Z"
      message: Invalid route kinds
      observedGeneration: 5
      reason: InvalidRouteKinds
      status: "False"
      type: ResolvedRefs
      name: udp-5300
      supportedKinds: []
      kind: List
      metadata:
      resourceVersion: ""

[CH3CHO]

请 @EndlessSeeker 看一下

[yudin-s]

For that Gateway listener, no: Higress is rejecting UDP, not just missing a UDPRoute object.

The status is coming from the listener protocol validation. In the current Gateway API conversion code the supported listener protocols are HTTP, HTTPS, TLS, TCP, and Higress/Istio's HBONE case. UDP is intentionally not in that set, so it falls through to:

protocol "UDP" is unsupported

That also matches your status:

conditions:
  - type: Accepted
    status: "False"
    reason: UnsupportedProtocol
    message: protocol "UDP" is unsupported
supportedKinds: []

supportedKinds: [] is the second important signal. The listener cannot attach UDPRoute because Higress does not currently advertise UDP as a supported Gateway listener protocol there. TCP is different: the code has a TCP path and maps it to TCPRoute, but UDP is not handled the same way.

So for v2.2.3, I would not expect protocol: UDP + UDPRoute to work through Higress Gateway API. If the backend can be exposed as TCP, use protocol: TCP with a TCPRoute. If it must be UDP, this likely needs a Higress feature request or a different Kubernetes Service/L4 load-balancer path outside Higress Gateway API.

If that explains the status, please mark the answer so others do not chase the allowedRoutes part first.