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VMWARE Teaming across seperate cisco switches (not in a stack)

Is it possible to have the VMWare and ESX Servers connected to two seperate 3750 switches (NOT IN A STACK) that in turn connects back to a core switch and run HA on the ESX VMWARE Servers?

I know you can do by running etherchannel from two cisco switches in the same stack but what if the two cisco switches were no in a stack and not possible to stack, can this be done or would there be an IP Address or ARP issue?

10 REPLIES
Hall of Fame Super Bronze

Re: VMWARE Teaming across seperate cisco switches (not in a stac

No, it can't be done as the switch will detect the same MAC Address coming from the VMWare servers which will cause a flap on each switch's MAC Address Table.

HTH,

___

Edison.

New Member

Re: VMWARE Teaming across seperate cisco switches (not in a stac

thank you for the quick response on this.

I take it if the two cisco 3750 switches were in a stack and we had etherchannel or lacp to the ESX then it can be done or if the ESX goes into two seperate blades in a core switch it should be ok yes?

Hall of Fame Super Bronze

Re: VMWARE Teaming across seperate cisco switches (not in a stac

Correct. The issue is with the source device sending the same MAC Address via different switchports that aren't members of an etherchannel.

The stack allows you to etherchannel across different physical hardware (same goes for modular hardware such as 6500 and 4500) but you can't bundle 2 switchports from different logical hardware.

IIRC, VMWare allows some kind of feature where you don't have to etherchannel on the switches and the server can have dual links connected to the switch. Isn't that HA? I thought LB required the etherchannel while HA didn't. Haven't played with VMWare in years.

New Member

Re: VMWARE Teaming across seperate cisco switches (not in a stac

not sure to be honest with you as someone else deals with the VMWare bit.

The guy reckons the VMWare servers are not sending the same MAC address but send the same IP address and need to load balence

Hall of Fame Super Bronze

Re: VMWARE Teaming across seperate cisco switches (not in a stac

But HA != LB. I'm not sure how you are going to load balance without sending the same MAC Address.

I believe with HA, one server is sitting there on Hot Standby and kicks up the minute the primary server goes down.

If that's the case, you do nothing at the switches and the configuration is done at the server. It will work on separate switches.

__

Edison.

New Member

Re: VMWARE Teaming across seperate cisco switches (not in a stac

thats a good point.

Going to push this back to the server guys and have a chat with them

thanks allot for this

Re: VMWARE Teaming across seperate cisco switches (not in a stac

We do it with 2960's. We have two switches in the top-of-rack both carrying the same VLAN. An EXS NIC goes into each switch. The team is active/passive otherwise you will get the MAC flap as Edison stated.

New Member

Re: VMWARE Teaming across seperate cisco switches (not in a stac

but thats not HA whereby the VM servers are active/active though. you have active/backup

Re: VMWARE Teaming across seperate cisco switches (not in a stac

Have mutltiple connections to your vswitch. I'm not a VM guy so don't take my word as gospel.

Hall of Fame Super Bronze

Re: VMWARE Teaming across seperate cisco switches (not in a stac

http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/vmware/VMware.html#wp696886

No Etherchanneling is mentioned, just 802.1q trunks.

HTH,

__

Edison.

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