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docs/user-guide/exposing-tcp-udp-services.md

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+# Exposing TCP and UDP services
+
+Ingress does not support TCP or UDP services. For this reason this Ingress controller uses the flags `--tcp-services-configmap` and `--udp-services-configmap` to point to an existing config map where the key is the external port to use and the value indicates the service to expose using the format:
+`<namespace/service name>:<service port>:[PROXY]:[PROXY]`
+
+It is also possible to use a number or the name of the port. The two last fields are optional.
+Adding `PROXY` in either or both of the two last fields we can use Proxy Protocol decoding (listen) and/or encoding (proxy_pass) in a TCP service (https://www.nginx.com/resources/admin-guide/proxy-protocol/).
+
+The next example shows how to expose the service `example-go` running in the namespace `default` in the port `8080` using the port `9000`
+
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: tcp-configmap-example
+data:
+  9000: "default/example-go:8080"
+```
+
+Since 1.9.13 NGINX provides [UDP Load Balancing](https://www.nginx.com/blog/announcing-udp-load-balancing/).
+The next example shows how to expose the service `kube-dns` running in the namespace `kube-system` in the port `53` using the port `53`
+
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: udp-configmap-example
+data:
+  53: "kube-system/kube-dns:53"