Build An Etherchannel: How And Why

CCNA and CCNP candidates are well versed in Spanning Tree Protocol, and one of the major advantages of STP is that it also works with little or no additional configuration. This is a situation where STP works against us a little, then it prevents loops change, which is the situation when two keys have multiple links.

One would think that if you have two physical links between the two windows, two times more data to another, as if it were a single connection. STP does not, but to prevent the loop switching, one of the channels are blocked.

SW1 and SW2, two types of physical connections, ports and fast0/11 fast 0 / 12, we see here on SW1 on port 0 / 11 is the traffic. Another STP port in blocking mode (BLK).

SW1 # show vlan 10

(Treatment of clarity over some)

STS interface type cost Prio.Nbr

Fa0/11 Root FWD 19 128.11 P2P

Fa0/12 ALTNER P2P BLK 19 128.12

While STP is helping us change the loops, STP is also hurting us to use a path very valid between SW1 and SW2. We can literally double the bandwidth between two switches, when we are in this direction, which is currently blocked.

The secret of using the EtherChannel configuration currently blocked path. An EtherChannel is simply a logical concentration of 2 to 8, the physical connection between two Cisco switches.

Configuring an EtherChannel is very simple. Use the 1-channel mode on each port, you EtherChannel. Of course, this must be on both switches, if you configure an EtherChannel on a button and not to do so, and the ports on the other side to change the protocol, and to remain there.

The beauty is that the STP EtherChannel EtherChannel marriage. If all the physical connections within the EtherChannel do not go see STP and STP not new. While movement between the two systems seems to have slowed, the delay in transmission by a recalculation of the STP avoid. An EtherChannel, we also offer the possibility of multiple physical links at a time.

Proceed as follows for these ports to an EtherChannel:

SW1 # conf t

Type the commands, one per line. The end of the CNTL / Z.

SW1 (config) # interface fast 0 / 11

SW1 (config-if) # channel-mode-1

Creating a port-channel interface port-channel 1

SW1 (config-if) # interface fast 0 / 12

SW1 (config-if) # channel-mode-1

SW2 # conf t

Type the commands, one per line. The end of the CNTL / Z.

SW2 (config) # int fast 0 / 11

SW2 (config-if) # channel-mode-1

SW2 (config-if) # int fast 0 / 12

SW2 (config-if) # channel-mode-1

The “Show interface root” and “Show-VLAN Spanning Tree-10″ are used to configure EtherChannel.

SW2 # show interface root (writing for some clarity)

Port Mode Encapsulation Status Native vlan

PO1 desirable 802.1q trunking 1

SW2 # show vlan 10 (publishing more, for some clarity)

STS interface type cost Prio.Nbr

PO1 LDes P2P FWD 12 128.65

Before contacting EtherChannel here, we saw individual ports. Now we see “PO1″, which is the interface salon1. “This is the logic of the interface created, if an EtherChannel is. We are now with the two physical paths between two switches in time!

It is a great advantage in the undertaking, more than one. Normally, when the only way to open Trunking between two windows, there is a delay, while another way is open – close to a minute, in some situations. We will now de-Port 0 / 11 SW2 and the impact on the EtherChannel.

SW2 # conf t

Type the commands, one per line. The end of the CNTL / Z.

SW2 (config) # int fast 0 / 11

SW2 (config-if) # shutdown

3w0d:% LINK-5-CHANGED: Interface FastEthernet0/11, changed
National management definition

SW2 # vlan, more than 10

VLAN0010

Spanning Tree Protocol enabled ieee

STS interface type cost Prio.Nbr

PO1 LDes P2P FWD 19 128.65

SW2 # show interface root

Port Mode Encapsulation Status Native vlan

PO1 desirable 802.1q trunking 1

The EtherChannel not go! STP EtherChannel see it as a single link, where STP is, nothing happens.

The creation of an EtherChannel and how can your network is an essential skill for CCNA and CCNP success, and it is very useful for the work that good. Make sure you are comfortable with the construction of a Cisco exams!