EtherChannel

[j4ss]

how the etherchannel works across 2 catalyst 6500 series(2 link from server/host. 1st link to catalyst switch 1 and 2nd link to catalyst switch 2)?

[konigl]

EtherChannel from a single server/host with 2 network cards, each connected to a different Catalyst 6500 switch, will not work, if I understand your post correctly. A single EtherChannel involves 2 and only 2 devices; it cannot be split among 3 or more.

2 cards to the same switch would work. Or 4 cards in the server/host would work, with 2 connecting to switch 1 as an EtherChannel, and the other 2 connecting to switch 2 as a separate EtherChannel.

If you are trying to connect the server/host to 2 different switches for redundancy or fault tolerance, using only 2 network connections, then you are either "multihoming" (with both network connections active); or you are doing something with the 2 network connections like a "hot standby" (1 active network connection, and 1 passive but patched in just-in-case), where the server monitors the link state and throughput on the 1st network connection and activates the 2nd one automatically if/when the 1st fails.

Hope this helps.

[j4ss]

Thanks for the reply, i'm just confuse, according to cisco's documents about etherchannel, no requirement for etherchannel link must be in the same port or same module but it must be in the same VLAN.

[j4ss]

Catalyst There are two possible hashing algorithms,

Cisco Series.

depending on the Supervisor hardware. The hash

is a seventeenth degree polynomial implemented

in hardware that, in all cases, takes the MAC, IP

address, or IP TCP/UDP port number and applies

the algorithm to generate a three bit value. This is

done separately for both source and destination

addresses. The results are then XORd to generate

another three−bit value that is used to determine

which port in the channel is used to forward the

packet. Channels on the Catalyst 6000 can be

formed between ports on any module, and can be

up to eight ports.

− Best Practices for Catalyst 6500/6000 Series and Catalyst 4500/4000 Series Switches Running Cisco

6500/6000

i do think so can bundle the link across switches to form etherchanel or i misunderstood the article.

− Best Practices for Catalyst 6500/6000 Series and Catalyst 4500/4000 Series Switches Running Cisco

6500/6000