New port number for new format global discovery

config/config.go

@@ -144,7 +144,7 @@ type NodeConfiguration struct {
 
 type OptionsConfiguration struct {
 	ListenAddress      []string `xml:"listenAddress" default:"0.0.0.0:22000"`
-	GlobalAnnServer    string   `xml:"globalAnnounceServer" default:"announce.syncthing.net:22025"`
+	GlobalAnnServer    string   `xml:"globalAnnounceServer" default:"announce.syncthing.net:22026"`
 	GlobalAnnEnabled   bool     `xml:"globalAnnounceEnabled" default:"true"`
 	LocalAnnEnabled    bool     `xml:"localAnnounceEnabled" default:"true"`
 	LocalAnnPort       int      `xml:"localAnnouncePort" default:"21025"`
@@ -362,6 +362,12 @@ func Load(rd io.Reader, myID protocol.NodeID) (Configuration, error) {
 		}
 	}
 
+	// The global discovery format and port number changed in v0.9. Having the
+	// default announce server but old port number is guaranteed to be legacy.
+	if cfg.Options.GlobalAnnServer == "announce.syncthing.net:22025" {
+		cfg.Options.GlobalAnnServer = "announce.syncthing.net:22026"
+	}
+
 	return cfg, err
 }