Part 3: Cisco Switch commands reference guide

Today we will going to talk about the Cisco commands used on the router and the switch and how they are configured. 

Here we start with the part 3 where we will start with the some of the Cisco switch commands. We already discuss some of the commands in part one and two as well

Fig 1.1- Spanning Tree Topology

STP optimization
NDNA_SW(config)#spanning-tree vlan 50 root primary 
NDNA_SW(config)#spanning-tree vlan 50 root secondary 
NDNA_SW(config)#spanning-tree [vlan 50] priority 8192

Changing the STP mode
NDNA_SW(config)#spanning-tree mode rapid-pvst 
(options: mst, pvst, rapid-pvst)

Enabling portfast and BPDU guard on an interface
NDNA_SW(config-if)#spanning-tree portfast 
NDNA_SW(config-if)#spanning-tree bpduguard enable

Changing port cost
NDNA_SW(config-if)#spanning-tree [vlan 50] cost 25

Bundling interfaces into an etherchannel
NDNA_SW(config-if)#channel-group 1 mode on 
(options: auto, desirable, on)

STP verification and troubleshooting
NDNA_SW# show spanning-tree
NDNA_SW# show spanning-tree interface fa0/5
NDNA_SW# show spanning-tree vlan 50
NDNA_SW# show spanning-tree [vlan50] root
NDNA_SW# show spanning-tree [vlan50] bridge
NDNA_SW# show etherchannel 1
NDNA_SW# debug spanning-tree events

Enabling or disabling CDP
NDNA_SW# show cdp
NDNA_SW# show cdp interface fa0/5
NDNA_SW# show cdp neighbors
NDNA_SW# show cdp neighbors detail
NDNA_SW# show cdp entry *
NDNA_SW# show cdp entry NDNA_SW2