What Is Etherchannel?

EtherChannel ဆိုတာ Cisco switches ေတြေပၚမွာ အဓိကသံုးတဲ႔ a port link aggregation technology (သို႔မဟုတ္) port-channel architecture တစ္ခုျဖစ္တယ္ EtherChannel က switches ၊ routers နဲ႔ servers ေတြႀကားမွာ fault-tolerance and high-speed links ေတြရဖို႔အတြက္ physical Ethernet links ေတြကို group တစ္ခုဖြဲ႔ျပီး one logical Ethernet link တစ္ခုအေနနဲ႔ တည္ေဆာက္ေပးနိုင္တယ္။       An EtherChannel ကို Fast, Gigabit or 10-Gigabit Ethernet ports ေတြမွာ active ports ကို two ports ကေန eight ports အထိ create လုပ္လို႔ရတယ္။ေနာက္ထပ္ inactive (failover) ports အေနနဲ႔ an additional one port ကို ထပ္ထည္႔လို႔ရေသးတယ္။အဲ႔ port က active port တစ္ခုခု fail ျဖစ္ျပီဆိုတာနဲ႔ သူက active port အေနနဲ႔အလုပ္လုပ္တယ္။ EtherChannel ကို အဓိကအေနနဲ႔ backbone network မွာသံုးတယ္ ၊ ဒါေပမယ္႔ end user machines ေတြကို connect လုပ္တဲ႔ေနရာမွာလည္းသံုးနိုင္တယ္

EtherChannel technology ကို Kalpana က 1990 အေစာပိုင္းေလာက္ကတီထြင္ခဲ႔တယ္။It was later acquired by Cisco Systems in 1994. ႏွစ္ 2000 ေလာက္မွာ IEEE (Institute of Electrical and Electronics Engineers) အဖဲြ႔က open standard version of EtherChannel အေနနဲ႔ 802.3ad ကို ျပဌာန္းခဲ႔တယ္ 

Etherchannel က load balancing လုပ္ဖို႔ နည္းလမ္းေကာင္း တစ္ခုျဖစ္တယ္။

အေပၚကပံုကိုၾကည္႔ျခင္းအားျဖင္႔ etherchannel က the switch ports ေတြကိုေပါင္းျပီး a one link ကဲ႔အလုပ္လုပ္ေပးေနတာကိုေတြရတယ္။ က်ြန္ေတာ္တို႔မွာ switches ႏွစ္ခုၾကားမွာ 1 Gigabyte links four links ရွိတယ္။ Etherchannel  က အဲ႔ ports ေတြကို 4 Gigabyte logical link တစ္ခုအေနနဲ႔  ေပါင္းပစ္တယ္။ Etherchannel မွာ two protocols ရွိတယ္

1.Port Aggregation Protocol(PAGP)

2.Link Aggregation Control Protocol(LACP)

1- PAGP ( Port Agg Protocol )

– PAGP is a Cisco proprieraty protocol.

– Port modes of PAGP are AUTO , DISERABLE and ON ( Best path ) .

2- LACP ( Link Agg Protocol )

– LACP is not a Cisco proprieraty protocol, it is an industry standart. ( 802.3AD )

– Port modes of  LACP are PASSIVE , ACTIVE and ON

The etherchannel မွာ types က two types ရွိတယ္။
1.   LAYER – 2 ETHERCHANNEL
2.   LAYER – 3 ETHERCHANNEL 

1- LAYER – 2 ETHERCHANNEL

Layer – 2 etherchannel is used on Layer -2 switches like Cisco 2960 etc.

CONFIGURING LAYER – 2 ETHERCHANNEL

SWITCH_A(conf)#interface range Fa0/23 - 24

SWITCH_A(conf-if)#channel protocol pagp

SWITCH_A(conf-if)#channel group 1 mode desirable

*** Same commands are implemented on SW B too. But just channel group mode is made “auto” to make a match between auto and desirable.

Configuration is verified with these commands :

SWITCH_A#show ip interface brief

SWITCH_A#show etherchannel detail

2- LAYER – 3 ETHERCHANNEL

Layer – 3 etherchannel is used on Layer -3 switches like Cisco 3750 etc.

Trick : It is enough that just one switch is Layer -3.

CONFIGURING LAYER – 3 ETHERCHANNEL

SWITCH_A(conf)#interface port-channel 1

SWITCH_A(conf-if)#no switchport

SWITCH_A(conf)#ip address 10.1.1.1 255.255.255.0

exit

SWITCH_A(conf)#interface range Fa0/23 - 24

SWITCH_A(conf-if)#no switchport

SWITCH_A(conf-if)#channel group 1 mode desirable

• Same configs are made for the other switch too. 
• All ports should be on the same speed and duplex mode. 
• Ports that are using for etherchannel should be in same VLAN or configured trunk.
• If you make a change in port-channel, that effects all the ports connected to it !