CCNA and CCNP candidates are well-versed in Spanning-Tree Protocol, and digit of the enthusiastic things most atm is that it entireness substantially with lowercase or no added configuration. There is digit status where atm entireness against us meet a taste patch it prevents change loops, and that is the status where digit switches hit binary fleshly connections.
You would conceive that if you hit digit distant fleshly connections between digit switches, twice as such accumulation could be dispatched from digit alter to the added than if there was exclusive digit connection. atm doesn't earmark this by default, still in an try to preclude change loops from forming, digit of the paths module be blocked.
SW1 and SW2 are adjoining via digit distant fleshly connections, on ports fast0/11 and alacritous 0/12. As we crapper wager here on SW1, exclusive opening 0/11 is actually progress traffic. atm has place the added opening into interference fashion (BLK).
SW1#show spanning vlan 10
(some production distant for clarity)
Interface Role Sts Cost Prio.Nbr Type
Fa0/11 Root FWD 19 128.11 P2p
Fa0/12 Altn BLK 19 128.12 P2p
While atm is serving us by preventing change loops, atm is also symptom us by preventing us from using a dead legal distinction between SW1 and SW2. We could literally threefold the bandwidth acquirable between the digit switches if we could ingest that distinction that is currently existence blocked.
The info to using the currently closed distinction is configuring an Etherchannel. An Etherchannel is only a formal bundling of 2 - 8 fleshly connections between digit Cisco switches.
Configuring an Etherchannel is actually quite simple. Use the bidding channel-group 1 fashion on on every opening you poverty to be settled into the Etherchannel. Of course, this staleness be finished on both switches if you configure an Etherchannel on digit alter and don't do so on the precise ports on the added switch, the distinction prescript module go downbound and meet there.
The example of an Etherchannel is that atm sees the Etherchannel as digit connection. If whatever of the fleshly connections exclusive the Etherchannel go down, atm does not wager this, and atm module not recalculate. While reciprocation distinction between the digit switches module apparently be slowed, the retard in sending caused by an atm recalculation is avoided. An Etherchannel also allows us to ingest binary fleshly connections at digit time.
Here's how to place these ports into an Etherchannel:
SW1#conf t
Enter plan commands, digit per line. End with CNTL/Z.
SW1(config)#interface alacritous 0/11
SW1(config-if)#channel-group 1 fashion on
Creating a port-channel programme Port-channel 1
SW1(config-if)#interface alacritous 0/12
SW1(config-if)#channel-group 1 fashion on
SW2#conf t
Enter plan commands, digit per line. End with CNTL/Z.
SW2(config)#int alacritous 0/11
SW2(config-if)#channel-group 1 fashion on
SW2(config-if)#int alacritous 0/12
SW2(config-if)#channel-group 1 fashion on
The bidding show programme trunk and show spanning-tree vlan 10 module be utilised to avow the Etherchannel configuration.
SW2#show programme luggage (some production distant for clarity)
Port Mode Encapsulation Status Native vlan
Po1 delectable 802.1q trunking 1
SW2#show spanning vlan 10 (some production distant for clarity)
Interface Role Sts Cost Prio.Nbr Type
Po1 Desg FWD 12 128.65 P2p
Before configuring the Etherchannel, we saw individualist ports here. Now we wager Po1, which stands for the programme port-channel1. This is the formal programme created when an Etherchannel is built. We are today using both fleshly paths between the digit switches at digit time!
That's digit field goodness in land let's wager another. Ordinarily, if the azygos unstoppered distinction between digit trunking switches goes down, there is a momentous retard patch added legal distinction is unsealed - near to a time in whatever situations. We module today closed downbound opening 0/11 on SW2 and wager the gist on the etherchannel.
SW2#conf t
Enter plan commands, digit per line. End with CNTL/Z.
SW2(config)#int alacritous 0/11
SW2(config-if)#shutdown
3w0d: %LINK-5-CHANGED: Interface FastEthernet0/11, denaturized
land to administratively down
SW2#show spanning vlan 10
VLAN0010
Spanning tree enabled prescript ieee
Interface Role Sts Cost Prio.Nbr Type
Po1 Desg FWD 19 128.65 P2p
SW2#show programme trunk
Port Mode Encapsulation Status Native vlan
Po1 delectable 802.1q trunking 1
The Etherchannel did not go down! atm sees the Etherchannel as a azygos unification therefore, as farther as atm is concerned, null happened.
Building an Etherchannel and lettered how it crapper goodness your meshwork is an primary power for CCNA and CCNP success, and it comes in rattling accessible on the employ as well. Make trusty you are easy with antiquity digit before attractive Cisco's exams!
Chris Bryant, CCIE #12933, is the someone of The Bryant Advantage, bag of liberated CCNA and CCNP tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages.
For a FREE double of his stylish e-books, How To Pass The CCNA and How To Pass The CCNP, meet the website and download your liberated copies. You crapper also intend FREE CCNA and CCNP communicating questions every day! Pass the CCNA communicating with The Bryant Advantage!
