200 301 pdf

200 301 pdf.FaO/12 GiO/1 GiO/2 FW Desg 19 128.12 D Desg FW 4 128.25 D FW Root 4 128.26 D P2p P2p P2pExample 2-1 begins with the output of the show spanning-tree vlan10 command executed on SW1. This command lists three main sets of information first: one about the root switch, a second about the local switch, and finally about the interface role and status. In this example, SW1 has its own BID as the root, and there is even a specific statement "The Bridge is theroot", making it clear that SW1 is now the root of the VLAN 10 STP topology.Next, compare the second half of the example using the same command highlighted on SW2. SW2 lists SW1's BID details as the root, in other words, SW2 has given permission to the fact that SW1 won the election. "SW1 will list its own (different) BID details after the BID details of the root.The output also identifies some default values. First. each switch lists the priority portion of the BID as a single number: 32778. this value is derived from the sum of the default priority of 32768 and VLAN10 for a total of 32778. this output also shows the interface overhead for some FastEthernet and GigabitEthernet interfaces,19 and 4 respectively by default.Finally, the bottom of the show spanning-tree command output lists each "interface" of the VLAN, including trunking, with the STP port role and port status. For example, on switch SW1, the output lists three interfaces containing a Desg for the designated port (DP) and a FWD state for forwarding. sw2 lists three interfaces, two DPs, and a root port, so all three are in the FWD (i.e., forwarding) state.Example 2-1 shows a lot of important STP information, but the other two commands shown in Example 2-2 do a better job of listing BID information in a more concise form. The first is the show spanning-treeroot command, which lists the root BID for each VLAN. this command also lists a few other details, such as the root overhead and root port of the local switch. The other command is show spanning-tree vlan 10bridge, which breaks down the BID into its component parts. In this example, it shows SW2's default priority of 32768, the VLANID value of 10, and the MAC address.Example 2-2 Listing the Root and Local Switch BIDs on Switch SW2 30 Chapter 2 Configuring Spanning Tree Protocol (STP)SW2# show spanning-tree rootVlan Root ID Root Cost Hello Time Max Age Fwd DlyRoot PortVLAN0001 VLAN0010 VLAN0020 VLAN0030 32769 32778 32788 32798 1833.9d5d.c900 1833.9d7b.0e80 1833.9d7b.0e80 1833.9d7b.0e80 23 4 4 4 4 2 2 2 2 2 20 20 20 20 20 15Gi0 /l 15Gi0/2. 15GiO/2 15GiO/2