Port aggregation, etherchannel, bonding part1

Setting up well designed network topology is one of the biggest challenge ever faces by Network Administrator all time, now a day 99.99% companies or organizations are totally depends upon Internet to carry out day to day task. Feasibility and the stability of network connection may greatly impact  the smoothness and overall growth of companies.

Network will often span across multiple switches and routers accordingly with the size of organization and range of services they are delivering to the end customers, and coverage of services will also influenced the complexly of network setup. Let come to the topic now.

Multiple switches in the network environment means there are huge chances of looping and broadcasting , which is never wish to exist in the network environment by network administrators.

To prevent or to predict future failures in the networking setup, administrator has to  think and an illustrates connectivity of every port on the networking devices like switch in the planned manner,

So today's topic is all about how to bundling switch ports , in Cisco networking terminology they called it Etherchannel or Port aggregation.

Port aggregation allow us bundling of multiple physical port together so form a Logical port, To eliminate the possibility of switching loops, STP treat this logical port as a  normal single physical port. 

If port aggregation is done on Ethernet port then it's called Ether channel, for fast Ethernet port  it's called  Fastetherchannel and Aggregation of Gig port, we called it Gigabitetherchannel , 10 gig etherchannel is also configurable .

 At maximum only 8 port will remain active in A single Etherchannel.

Maximum no of etherchannel supported on single switch is varies from platform to platform but in most of cases it do support 64 or 128 

Configuration of trunk link over single physical port create single point of failure as that port goes down trunk link will lost. Also suffers congestion or traffic bottleneck as all communication is happening through that port.

If you suppose to create multiple trunk links between switches then this may create switching loops or STP may disabled some ports to prevent loops. To rescue from above drawback, etherchannel comes into play.

Etherchannel can be formed over access port as well as over trunk ports. Implementation of etherchannel over access port provide increased bandwidth and redundancy to a host and servers, how ever those host and servers should support port aggregation protocols. And implementation of etherchannel over trunk link provide greater bandwidth and redundancy for switched environment.

If specific port  in the etherchannel fails then traffic will be distributed across other active ports seemlessly. 

Etherchannel to become active, following requirement should be meet exactly,

1. Port speed should be same.

2. Port duplex setting need to be same.

3. Switch STP setting should be same , either it be CST, PVST,PVST+,RSTP or MST.

4. Port vlan membership settings .if etherchannel is forming over access port.

5. Allowed vlan and Native vlan and encapsulation protocolshould be same if etherchannel is forming  over trunk link.

6.