... reserved. ICND v2.0— 3-1 1 Spanning- Tree Recalculation© 2002, Cisco Systems, Inc. All rights reserved. ICND v2.0— 3- 15 Summary•STP is a bridge-to-bridge protocol used to maintain a loop-free network. ... v2.0— 3-8 Spanning- Tree Port States (Cont.)© 2002, Cisco Systems, Inc. All rights reserved. ICND v2.0— 3-1 3Rapid Spanning- Tree Protocol © 2002, Cisco Systems, Inc. All rights reserved. ICND v2.0— 3-1 2 Spanning- Tree ... blocking state. Spanning- Tree Protocol © 2002, Cisco Systems, Inc. All rights reserved. ICND v2.0— 3-1 0 Spanning- Tree Example© 2002, Cisco Systems, Inc. All rights reserved. ICND v2.0— 3-1 4Rapid Transition...