56 CHAPTER 4: USING RESILIENCE FEATURESDefault Behavior This section contains important information to note when using the RSTPand Fast Start features, particularly if you already have existing Switch4400 units in your network with an older version of software.RSTP DefaultBehaviorWhen using the RSTP feature on version 2.0 or later software, note thefollowing: A Switch with version 2.0 factory loaded will have RSTP enabled bydefault. A Switch with version 1.0 software will have STP disabled by default. A Switch that you upgrade to version 2.0 software will retain itssettings from prior to the upgrade, for example, if STP is disabled priorto the upgrade, it will stay disabled even though version 2.0 has RSTPenabled by default. However, if you initialize an upgraded Switch, thiswill clear the settings and the Switch will then assume all the version2.0 default settings, including RSTP enabled. If you connect a new Switch with version 2.0 already loaded to a stackof upgraded units, all the upgraded units will assume the defaultsettings of the new Switch, that is, they will have RSTP enabled bydefault.Fast Start DefaultBehaviorWhen using the Fast Start feature on version 2.0 or later software, notethe following: A Switch with version 2.0 factory loaded will have Fast Start enabledby default on the front panel ports, and disabled on any expansionmodule ports. A Switch with version 1.0 software will have Fast Start disabled bydefault. A Switch that you upgrade to version 2.0 software will retain itssettings from prior to the upgrade only if any manual settings wereconfigured. However, if the Switch was still operating in its defaultstate, then upon upgrade it will assume version 2.0 Fast Start defaultsettings. If you initialize an upgraded Switch, this will clear the settings and theSwitch will assume all the default version 2.0 settings, that is, it willhave Fast Start enabled.
