CISCO SPANNING TREE PROTOCOL (STP)
Spanning Tree Protocol (STP) is a Layer 2 link control protocol, ensuring redundancy of the route while avoiding network loops. For a network Layer 2 to operate correctly, between any two stations only one active path should occur. It has three steps, which are Find the root bridge, Find the root port (R), Find the designated port (D).
Exercise 1
Based on the Picture above, lets exercise and follow the command below,
SW1
hostname SW1
do show spanning-tree
SW2
hostname SW2
do show spanning-tree
SW3
hostname SW3
do show spanning-tree
VPC4
ip 172.16.1.1 255.255.255.0
ping 172.16.1.2
VPC5
ip 172.16.1.2 255.255.255.0
ping 172.16.1
EtherChannel
EtherChannel, or port-channel architecture, EtherChannel can be merged into one logical connection via several physical Ethernet connections. If an EtherChannel segment is failing, traffic previously brought over the failed connection moves to the remainder of the EtherChannel segments.
Now we will practice how to apply the etherchannel, Follow the command below,
hostname SW1
int range e0/0 - 1
channel-group 1 mode on
do show etherchannel summary
do show spanning-tree
hostname SW2
int range e0/0 - 1
no shutdown
channel-group 1 mode on
no shutdown
do show etherchannel summary
do show spanning-tree