diff --git a/conf/namespace/example.toml b/conf/namespace/example.toml
index 1816b03c..8cdf6024 100644
--- a/conf/namespace/example.toml
+++ b/conf/namespace/example.toml
@@ -3,5 +3,5 @@ namespace = "default"
 [frontend]
 
 [backend]
-instances = [ "127.0.0.1:4000" ]
+instances = [ "127.0.0.1:3306" ]
 selector-type = "random"
diff --git a/conf/proxy.toml b/conf/proxy.toml
index b688e429..5b73a37d 100644
--- a/conf/proxy.toml
+++ b/conf/proxy.toml
@@ -3,7 +3,7 @@
 [proxy]
 # addr = "0.0.0.0:6000"
 # tcp-keep-alive = true
-# require-backend-tls = true
+require-backend-tls = false
 
 # possible values:
 #   "" => disable proxy protocol.
@@ -26,7 +26,7 @@ graceful-close-conn-timeout = 15
 # possible values:
 #		"" => enable static routing.
 #		"pd-addr:pd-port" => automatically tidb discovery.
-# pd-addrs = "127.0.0.1:2379"
+pd-addrs = ""
 
 # possible values:
 #		0 => no limitation.
diff --git a/pkg/proxy/backend/authenticator.go b/pkg/proxy/backend/authenticator.go
index 77ed078c..4f1bafc8 100644
--- a/pkg/proxy/backend/authenticator.go
+++ b/pkg/proxy/backend/authenticator.go
@@ -214,7 +214,7 @@ loop:
 		if err != nil {
 			// tiproxy pp enabled, tidb pp disabled, tls disabled => invalid sequence
 			// tiproxy pp disabled, tidb pp enabled, tls disabled => invalid sequence
-			if pktIdx == 0 && auth.proxyProtocol {
+			if pktIdx == 0 {
 				return errors.Wrap(ErrBackendPPV2, err)
 			}
 			return err