2960s Flex stack and etherchannel/LACP

[Walsby1983]

Hello all, im after some advice.

I have setup 2 2960s with flexstack. I have setup a channel group (LACP) on G1/0/1 + G2/0/1 (cross stack) which connect to a storage box.

I'm a little stuck when it comes to the load balacing and fail over;

Do i use source IP or destination IP? or sourse MAC or destination MAC?

And would the command LACP direct-loadswap be the key to the failover?

Thanks in advance 

[Somasundaram Jayaraman]

Hi,

Src Mac - Dst Mac Load balancing:

==========================

++ For the 2950/2955/3550 series switch,  EtherChannel balances the traffic load across the links in a channel by  randomly associating a newly learned MAC address with one of the links  in the channel.

EtherChannel load balancing can use either source-MAC or  destination-MAC address forwarding.

With source-MAC address forwarding, when packets are forwarded to an  EtherChannel, the packets are distributed across the ports in the  channel based on the source-MAC address of the incoming packet. 

Therefore, to provide load balancing, packets from different hosts use  different ports in the channel, but packets from the same host use the  same port in the channel.

With destination-MAC address forwarding, when  packets are forwarded to an EtherChannel, the packets are distributed  across the ports in the channel based on the destination host MAC  address of the incoming packet.

Therefore, packets to the same  destination are forwarded over the same port, and packets to a different  destination are sent on a different port in the channel.

SRC IP- DST IP Load balance:

========================

when source-MAC address forwarding is used, load  distribution based  on the source and destination IP address is also  enabled for routed IP  traffic.

All routed IP traffic chooses a port  based on the  source and destination IP address. Packets between two IP  hosts always  use the same port in the channel, and traffic between any  other pair of  hosts can use a different port in the channel.

So basically the load-balance mechanism can be chosen based on the type of traffic passing through the etherchannel.

++ If the traffic is only layer 2 traffic, then we can prefer source mac-destination mac load balancing

++ If the traffic is a routed traffic, then use source-ip destination ip load balancing

The command "LACP direct-loadswap can be used for  only a single bundled port failure.

If a second failure occurs before  the first failure recovers, the loadshare bits for member links are  recomputed.

++ So this command ideally comes into place if a link in the port-channel fails.

Hope this helps.

Cheers

Somu

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[Walsby1983]

Ok i tried src-dest-mac ad ip and when i simulate a switch failure my running ping just times out until the switch i pulled the power out of comes back up. The storage box itself has 2 NICS which i've set up as lacp so they are one... Is it correct to set this and at the switch end also?

On another note the lacp direct-loadswap command doesn't appear to be available.