diff --git a/app/dns/nameserver.go b/app/dns/nameserver.go
index 277963d03..abbfb4085 100644
--- a/app/dns/nameserver.go
+++ b/app/dns/nameserver.go
@@ -7,12 +7,13 @@ import (
 	"v2ray.com/core/features/dns/localdns"
 )
 
+// IPOption is an object for IP query options.
 type IPOption struct {
 	IPv4Enable bool
 	IPv6Enable bool
 }
 
-type NameServerInterface interface {
+type Client interface {
 	Name() string
 	QueryIP(ctx context.Context, domain string, option IPOption) ([]net.IP, error)
 }
diff --git a/app/dns/server.go b/app/dns/server.go
index d7b9acd88..e25315ed0 100644
--- a/app/dns/server.go
+++ b/app/dns/server.go
@@ -20,7 +20,7 @@ import (
 type Server struct {
 	sync.Mutex
 	hosts          *StaticHosts
-	servers        []NameServerInterface
+	clients        []Client
 	clientIP       net.IP
 	domainMatcher  strmatcher.IndexMatcher
 	domainIndexMap map[uint32]uint32
@@ -29,7 +29,7 @@ type Server struct {
 // New creates a new DNS server with given configuration.
 func New(ctx context.Context, config *Config) (*Server, error) {
 	server := &Server{
-		servers: make([]NameServerInterface, 0, len(config.NameServers)+len(config.NameServer)),
+		clients: make([]Client, 0, len(config.NameServers)+len(config.NameServer)),
 	}
 	if len(config.ClientIp) > 0 {
 		if len(config.ClientIp) != 4 && len(config.ClientIp) != 16 {
@@ -47,22 +47,22 @@ func New(ctx context.Context, config *Config) (*Server, error) {
 	addNameServer := func(endpoint *net.Endpoint) int {
 		address := endpoint.Address.AsAddress()
 		if address.Family().IsDomain() && address.Domain() == "localhost" {
-			server.servers = append(server.servers, NewLocalNameServer())
+			server.clients = append(server.clients, NewLocalNameServer())
 		} else {
 			dest := endpoint.AsDestination()
 			if dest.Network == net.Network_Unknown {
 				dest.Network = net.Network_UDP
 			}
 			if dest.Network == net.Network_UDP {
-				idx := len(server.servers)
-				server.servers = append(server.servers, nil)
+				idx := len(server.clients)
+				server.clients = append(server.clients, nil)
 
 				common.Must(core.RequireFeatures(ctx, func(d routing.Dispatcher) {
-					server.servers[idx] = NewClassicNameServer(dest, d, server.clientIP)
+					server.clients[idx] = NewClassicNameServer(dest, d, server.clientIP)
 				}))
 			}
 		}
-		return len(server.servers) - 1
+		return len(server.clients) - 1
 	}
 
 	if len(config.NameServers) > 0 {
@@ -94,8 +94,8 @@ func New(ctx context.Context, config *Config) (*Server, error) {
 		server.domainIndexMap = domainIndexMap
 	}
 
-	if len(server.servers) == 0 {
-		server.servers = append(server.servers, NewLocalNameServer())
+	if len(server.clients) == 0 {
+		server.clients = append(server.clients, NewLocalNameServer())
 	}
 
 	return server, nil
@@ -116,9 +116,9 @@ func (s *Server) Close() error {
 	return nil
 }
 
-func (s *Server) queryIPTimeout(server NameServerInterface, domain string, option IPOption) ([]net.IP, error) {
+func (s *Server) queryIPTimeout(client Client, domain string, option IPOption) ([]net.IP, error) {
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second*4)
-	ips, err := server.QueryIP(ctx, domain, option)
+	ips, err := client.QueryIP(ctx, domain, option)
 	cancel()
 	return ips, err
 }
@@ -156,7 +156,7 @@ func (s *Server) lookupIPInternal(domain string, option IPOption) ([]net.IP, err
 	if s.domainMatcher != nil {
 		idx := s.domainMatcher.Match(domain)
 		if idx > 0 {
-			ns := s.servers[s.domainIndexMap[idx]]
+			ns := s.clients[s.domainIndexMap[idx]]
 			ips, err := s.queryIPTimeout(ns, domain, option)
 			if len(ips) > 0 {
 				return ips, nil
@@ -168,13 +168,13 @@ func (s *Server) lookupIPInternal(domain string, option IPOption) ([]net.IP, err
 		}
 	}
 
-	for _, server := range s.servers {
-		ips, err := s.queryIPTimeout(server, domain, option)
+	for _, client := range s.clients {
+		ips, err := s.queryIPTimeout(client, domain, option)
 		if len(ips) > 0 {
 			return ips, nil
 		}
 		if err != nil {
-			newError("failed to lookup ip for domain ", domain, " at server ", server.Name()).Base(err).WriteToLog()
+			newError("failed to lookup ip for domain ", domain, " at server ", client.Name()).Base(err).WriteToLog()
 			lastErr = err
 		}
 	}