# 看下面的实例,这是一台4506三层交换机
C4506#sh spanning-tree root
Root Hello Max Fwd
Vlan Root ID Cost Time Age Dly Root Port
---------------- -------------------- --------- ----- --- --- ------------
VLAN0110 32878 c464.13e1.e900 0 2 20 15
VLAN0120 32888 c464.13e1.e900 0 2 20 15
VLAN0130 32898 c464.13e1.e900 0 2 20 15
VLAN0140 32908 c464.13e1.e900 0 2 20 15
VLAN0170 32938 c464.13e1.e900 0 2 20 15
VLAN0180 32948 c464.13e1.e900 0 2 20 15
VLAN0190 32958 3cce.7325.3080 7 2 20 15 Po1
VLAN0200 32768 f8b1.5677.805f 20004 2 20 15 Gi6/32
VLAN0210 32978 c464.13e1.e900 0 2 20 15
VLAN0230 32998 c464.13e1.e900 0 2 20 15
VLAN0310 33078 c464.13e1.e900 0 2 20 15
VLAN0601 33369 c464.13e1.e900 0 2 20 15
VLAN0700 33468 c464.13e1.e900 0 2 20 15
VLAN0800 33568 c464.13e1.e900 0 2 20 15
VLAN0900 33668 c464.13e1.e900 0 2 20 15
VLAN0920 33688 c464.13e1.e900 0 2 20 15
VLAN1694 34462 c464.13e1.e900 0 2 20 15
# 对 VLAN 110 而言,这台交换机就是根交换机。它的 Root ID 是 c464.13e1.e900
但是这个mac地址用命令 sh mac add 查不到,换句话说,c464.13e1.e900这个mac地址不是端口上能查到的mac地址
它应该是系统里面的mac地址