Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 1081

The range is from 4 to 30. The default is 15 seconds. • Change the hello-time parameter (the BPDU transmission interval). PROTOCOL SPANNING TREE mode hello-time seconds NOTE: With large configurations (especially those with more ports) Dell Networking recommends increasing the hello-time. The range is from 1 to 10. the default is 2 seconds. • Change the max-age parameter (the refresh interval for configuration information that is generated by recomputing the spanning tree topology). PROTOCOL SPANNING TREE mode max-age seconds The range is from 6 to 40. The default is 20 seconds. To view the current values for global parameters, use the show spanning-tree 0 command from EXEC privilege mode. Refer to the second example in Enabling Spanning Tree Protocol Globally. Modifying Interface STP Parameters You can set the port cost and port priority values of interfaces in Layer 2 mode. • Port cost - a value that is based on the interface type. The greater the port cost, the less likely the port is selected to be a forwarding port. • Port priority - influences the likelihood that a port is selected to be a forwarding port in case that several ports have the same port cost. The default values are listed in Modifying Global Parameters. To change the port cost or priority of an interface, use the following commands. • Change the port cost of an interface. INTERFACE mode spanning-tree 0 cost cost The range is from 0 to 65535. The default values are listed in Modifying Global Parameters. • Change the port priority of an interface. INTERFACE mode spanning-tree 0 priority priority-value Spanning Tree Protocol (STP) 1081