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2910al trunking with SAN server

Jay671
Advisor

2910al trunking with SAN server

Need some help. I am a bit confused about the trunking feature and fear I have set mine up incorrectly for my SAN traffic.
I purchased two of the 2910al switches strictly for SAN traffic.
I have a "SAN" vlan. In reading on trunking the documentation states that "For dynamic LACP trunk to operate in a VLAN other than default VLAN, GVRP must be enabled"
OK
So I did this, and I set the primary VLAN to be my SAN VLAN. Then I trunked the back module ports with 10 gig gbics together between the two switches.
My main switch now shows all traffic levels at the exact same, which I am assuming is because I made the primary VLAN the SAN vlan while trunking the two 10 gig ports also tagged for the SAN VLAN so it is basically replicating the traffic on all ports as if one now.
Is my assumption correct in this?
And is this normal, or did I set this whole thing up incorrectly?
If I did, can someone please show me an example of how it should be done or if you are currently doing this how you have it setup?

Reason I am asking, is the Server team is seeing high retransmission rates on the san links now.

Thanks in advance.

Jay
4 REPLIES
Olaf Borowski
Respected Contributor

Re: 2910al trunking with SAN server

Jay,
If the switches are for SAN traffic only, you don't need to create a special VLAN for that. Use VLAN1. Every port is assigned to VLAN 1 by default. Regarding trunking: If you want to aggregate the two 10Gig links that connect the switches to each other, use static LACP to do that. Create a static LACP trunk on both sides. By default, this trunk should be a member of VLAN 1 untagged. In regards to GVRP: This is a protocol used to propagate VLAN information. Example: If you create a VLAN 10 on switch A and have GVRP enabled on both switches, VLAN 10 automatically gets created on switch B. You still need to go to the switch and assign the appropriate ports to the new VLAN. I would recommend not to use it and create VLANs statically. This is more secure and less prone to errors. Example: If you delete a VLAN accidentally on one switch, it is automatically removed from all other switches. In your small setup, don't use GVRP. Is is not required for trunking/LACP. As long as you only have one VLAN (VLAN1), no tagging necessary.
Good luck,
Olaf
Jay671
Advisor

Re: 2910al trunking with SAN server

Thanks Olaf,

I might have played off the scale of the whole situation before. The SAN VLAN was created some time ago, and the two switches were basically a test for now to see what kind of performance increases we would see. Both switches being 48 ports, and all ports in use, if this works out to enhance performance, I have 8 more scheduled to be ordered and deployed.
With that said, I do understand what you are saying about the default VLAN, but since I already have the SAN VLAN in place I can just use that one. And from the sounds of it I basically have it setup pretty much the way you described. The ten gig link is trunked and untagged for the SAN VLAN, and all 48 ports are tagged with to the SAN VLAN.
Currently the switches are stacked but I plan on removing this as it has no benefit for me, and I mis-understood the term "stacked" in an HP environment when going off the equalogic recommendations.
But is it still normal to see traffic on one of the switches (currently the commander switch) all at the exact same level? I have not done trunking before so maybe this is normal, but just seems odd to me.

Thanks Again!
Jay671
Advisor

Re: 2910al trunking with SAN server

Forgot to mention, I do have other VLAN's on the switch, my management VLAN is on that switch as well.
Jay671
Advisor

Re: 2910al trunking with SAN server

OK,
so I made some changes, I removed stacking from both, turned off spanning tree, changed primary VLAN back to "DEFAULT" and trunked the ten gig ports using LACP with it untagged in the SAN VLAN. All ports are tagged to the SAN VLAN. THings seem to be running better but getting a lot of "High collision drop rate" errors on the switch. The SAN VLAN is set for Jumbo and flow control.
Was wondering, if Jumbo is turned on for the ports, does it still report high traffic on that port? Once in a while they do spike to 100%, but I typically see the errors when it is not spiked.
Is this normal?