EtherChannel Note

johnny_jiang

EtherChannel Advantage
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1. Combine multiple fast or gigabit ethernet into one logical port to increase bandwidth with lower cost.
2. Load balancing between bond links, two, four, eight links can be bond together.
3. Load balancing algorithm depends on device module
For instance, in a Cisco Catalyst 5500 switch platform, the load-balancing operation performs an X-OR calculation on the two lowest-order bits of the source and destination MAC address. An X-OR operation between a given pair of addresses will use the same link for all frames.On a Cisco Catalyst 6500 switch, the load-balancing operation can be performed on MAC address, IP address, or IP + TCP/User Datagram Protocol (UDP), depending on the type of Supervisor/Policy Feature Card (PFC) used.
4. EtherChannel bundles individual Ethernet links into a single logical link that provides bandwidth up to 1600 Mbps (Fast EtherChannel, full duplex) or 16 Gbps (Gigabit EtherChannel) between two Cisco Catalyst switches.
5. It provides automatic failover.
6. In EtherChannel, it is mandatory that all ports have the same speed, duplex setting, and VLAN information(access or trunk port with same allowed VLANs).
7. PAgP and LACP (802.3ad) will be used to automatically create etherchannel between switch.
8. STP takes etherchannel as one port, so physical ports in etherchannel will lose STP information.
9. Etherchannel can be configured as layer2 or layer3 interface.
10. Command for etherchannel
Switch(config)# interface port-channel 1Switch(config-if)# interface range fa 1/1 - 10Switch(config-if-range)# [no] switchportUse no keyword to disable layer 2 interface and convert to layer 3 interfaceSwitch(config-if-range)# channel-protocol {lacp|pagp}Switch(config-if-range)# channel-group 1 mode {active|desirable|auto|passive|on}For layer 3 interface, it is taken for granted that ip address is needed on port channel 1.Switch(config-if)# ip address 192.168.1.10 255.255.255.0
Assign Layer 3 addresses to the port-channel logical interface, not to the physical interfaces in the channel.
               
               
               

本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u1/42903/showart_428776.html