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Link aggregation and Cascading switches

ColmacIT
ColmacIT used Ask the Experts™
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I have 6 switches in a room with a dozen or so servers. Most of the servers have dual NIC's. Those that do have their NIC's teamed. here are my questions. Should each server be hooked to 2 ports on 1 switch or 1 port on 2 switches for redundancy in a cascading setup? Lastly does a switch LAG need to be configured to accomodate the teamed NIC's from the servers?

Thank you all in advance.
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Instructor
Top Expert 2015
Commented:
That is going to depend on your switches. If they are unstacked Cisco IOS switches, then both NIC's have to connect to one switch.

If the switches are stacked (2960 or 3750) or Nexus switches then you can (and probably should) connect the server to two different switches.

Author

Commented:
Funny you should mention that. Currently I have a mixed bag of linksys, netgear, dlink and cisco switches, but I am about to throw a 2960 in the mix. I am hoping to slowly replace all of the others with Cisco. In the mean time this Cisco switch will not be stacked if ever.

I actually had the servers  connected to 2 switches already. A srw2048 and a slm2048. I did not configure a LAG on either of them, and I really do not know how well it worked, but I did have switch redundancy. My switches were daisy chained and I am in the process of  re-wiring to more of a cascade design.
Don JohnstonInstructor
Top Expert 2015

Commented:
If the switches aren't stacked then you are not going to have true link agregation.

Author

Commented:
Will I have true link aggregation if they are plugged into 1 switch? If so do I need to configure the switch side as well as teaming the NIC's using the server software?

Thank you.
Don JohnstonInstructor
Top Expert 2015

Commented:
Will I have true link aggregation if they are plugged into 1 switch?

If the switch supports it and is configured, yes.

If so do I need to configure the switch side as well as teaming the NIC's using the server software?

Yes.