<br>In the following procedures, the specified interface must be one of these Layer 3 interfaces:<br><br>Routed port: a physical port configured as a Layer 3 port by entering the no switchport interface configuration command.<br><br><br>SVI: a VLAN interface created by using the interface vlan vlan_id global configuration command and by default a Layer 3 interface.<br><br><br>Etherchannel port channel in Layer 3 mode: a port-channel logical interface created by using the interface port-channel port-channel-number global configuration command and binding the Ethernet interface into the channel group. For more information, see the "Configuring Layer 3 EtherChannels" section.<br><br><br>http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/12112cea/3550scg/swhsrp.htm#xtocid4