fatedier/frp · error

not support proxy protocol version: %s

Error message

not support proxy protocol version: %s

What it means

Error "not support proxy protocol version: %s" thrown in fatedier/frp.

Source

Thrown at pkg/config/v1/validation/proxy.go:37

	"fmt"
	"slices"
	"strings"

	"k8s.io/apimachinery/pkg/util/validation"

	v1 "github.com/fatedier/frp/pkg/config/v1"
)

func validateProxyBaseConfigForClient(c *v1.ProxyBaseConfig) error {
	if c.Name == "" {
		return errors.New("name should not be empty")
	}

	if err := ValidateAnnotations(c.Annotations); err != nil {
		return err
	}
	if !slices.Contains([]string{"", "v1", "v2"}, c.Transport.ProxyProtocolVersion) {
		return fmt.Errorf("not support proxy protocol version: %s", c.Transport.ProxyProtocolVersion)
	}
	if !slices.Contains([]string{"client", "server"}, c.Transport.BandwidthLimitMode) {
		return fmt.Errorf("bandwidth limit mode should be client or server")
	}

	if c.Plugin.Type == "" {
		if err := ValidatePort(c.LocalPort, "localPort"); err != nil {
			return fmt.Errorf("localPort: %v", err)
		}
	}

	if !slices.Contains([]string{"", "tcp", "http"}, c.HealthCheck.Type) {
		return fmt.Errorf("not support health check type: %s", c.HealthCheck.Type)
	}
	if c.HealthCheck.Type != "" {
		if c.HealthCheck.Type == "http" &&
			c.HealthCheck.Path == "" {
			return fmt.Errorf("health check path should not be empty")

View on GitHub (pinned to 6c8a8d0a97)

Solutions

1. Set transport.proxyProtocolVersion to 'v1' or 'v2', or remove the field to disable the proxy protocol.
2. Make sure the frps server and the upstream load balancer support the selected proxy protocol version.

When it happens

Trigger: Raised by validateProxyBaseConfigForClient in pkg/config/v1/validation/proxy.go when transport.proxyProtocolVersion is set to a value other than "", "v1", or "v2".

Common situations: Typo in the proxy protocol version (e.g. "V2", "v3", "2") in the proxy config. Fix by setting transport.proxyProtocolVersion to "v1" or "v2", or omitting it.

AI-assisted analysis of fatedier/frp@6c8a8d0a97 (2026-08-15). Data as JSON: /api/errors/46aa1a98213545ff. Report an issue: GitHub.