VMware vSphere

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  • 1.  Load balancing and Failover order

    Posted Jul 22, 2012 06:02 PM

    Hi,

         I have the following scenario. One ESXi with 4 Gbps vmnics. The questions are:

    1) If I have a port group configured for "Route Based on the originating Virtual Port ID" in the Load Balancing Policy, and for the same port group I have the option box  "Override switch failover order" checked, where I have configured 3 of the vmnics as active adapters and the other remaining vmic as unused adapter, does the ESXi use the load balancing policy that I have configured (in this case "Route based on the originating port ID") between the three vmnics marked as active? Or it does use them in the order that they appear in the active adapters section?

    2) Suppossed I have configured the four ports in the physical switch in an etherchannel group in order to use "Route based on IP hash" load balancing policy. In that situation, may I configured for a certain port group to only used two active adapters and the other two ones as unused? In that case, ESXi would load balance using IP hash method but only in the two active adapters? Or it's a misconfigiuration and I shouldn't configure my nic teaming in that way?

    3) The official configuration guide says "NOTE IP-based teaming requires that the physical switch be configured with etherchannel. For all other options, etherchannel should be disabled.". How should I configured my virtual networking if I have some port groups that use load balancing policy based on IP hash and another ones use "Route based on the originating port ID". This is the case when I have for example two management ports using the same vSwitch with four vmnics (where they are configured as an Etherchannel in the physical switch). I would have one or more port groups for VMs that use IP hash method for load balancing, and the vmkernel ports por management use only one active adapter with no failback and load balancing as "based on originating port ID" as the best practices says.

    Now, the four vmnics are the same for all traffic. The ports in the physical switch must be configured in an etherchannel group because some port groups are gonna use IP hash method, but the other ones don't. The configuration guide says I SHOULD NOT use etherchannel if I'm not gonna use IP hash method, but I WILL use it, but only in one ore more port groups.

    Perhaps I cannot share the same vmnics for that situation.

    Lastly, this is a philosophical question. What is the difference between the "Route based on the originating port ID" and the "Route based on source MAC Hash" load balancing policy? What is the purpose of the second one? It is supposed that if I had two different MAC address in a VM, that would be because I had two different virtual nics inside the VM, which would be connected to two different port ID in the vSwitch, so I could use the first policy (based on the originating port ID). In other words, which would be the case where I had traffic incoming from the same vSwitch port ID  but with different source MAC Address, so I should chose the Source MAC Address load balancing method to discriminate the traffic?

    Thanks.

    Guido.



  • 2.  RE: Load balancing and Failover order
    Best Answer

    Posted Jul 22, 2012 09:13 PM

    1) As long as you override just vmnic selection, and do not change policy for that port group, it will use the policy configured at the vSwitch level, and use the 3 selected interface with that policy

    2) It should work, I don't think this is a problem for the switch to receive some packets on a subset of the agregation. I don't think Etherchannel is supported though (IIRC, this is a proprietary Cisco protocol, VMware only supports passive LACP, which corresponds to Port Channel in Cisco world. Fix me if I'm wrong !)

    3) I think it is all right, as I explained in 2), there is no special negociation with VMware teaming, the only important thing I'm aware is to configure port channel on the switch side if you decide to use IP hash (not doing this will lead to important issues)

    4) (self labeled) I think this may differ in some special cases like when the OS use the same MAC address for both nics (in-vm teaming) or if you are announcing multiple MAC address for the same nic (ESX in a VM for example would do that for its VM). Cases like this will impact differently this setting.

    Those are good question and I'm curious if anyone wants to elaborate on this !



  • 3.  RE: Load balancing and Failover order

    Posted Jul 22, 2012 11:18 PM

    Yannbizeul,

         Thank you for your response. I tell you what I think about them:

    1) OK

    2) OK.

    About your comment about Etherchannel. The way of configuring Etherchannel in cisco is through the "Port Channel" command. You use the "Port Channel" command to create a "virtual" group of ports, and afterward in each interface you use the "Channel-group" making reference to the "Port Channel" created before. In fact, the official VMware Networking Configuration Guide speaks about Etherchannel as I copy-pasted in the beginning of my question number 3.

    Perhaps you get confused about that because in the "Port Channel" you can configure the port channel mode (Etherchannel), where you use the same command (channel-group) to configure if the Port Channel is going to use LACP, PAgP or no negotioation at all, but everyones are in the end Etherchannel.

    I put here a reference guide of configuring Etherchannel in Cisco:

    http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.1/19ew/configuration/guide/channel.pdf

    3) OK

    4) Very good examples of two different cases.

    Thank you again.

    Guido.



  • 4.  RE: Load balancing and Failover order

    Posted Jul 23, 2012 02:39 AM

    Discussion moved from VMware ESXi 5 to VMware vSphere™ vNetwork

    Guido Gariup wrote:

    About your comment about Etherchannel. The way of configuring Etherchannel in cisco is through the "Port Channel" command. You use the "Port Channel" command to create a "virtual" group of ports, and afterward in each interface you use the "Channel-group" making reference to the "Port Channel" created before. In fact, the official VMware Networking Configuration Guide speaks about Etherchannel as I copy-pasted in the beginning of my question number 3.

    Perhaps you get confused about that because in the "Port Channel" you can configure the port channel mode (Etherchannel), where you use the same command (channel-group) to configure if the Port Channel is going to use LACP, PAgP or no negotioation at all, but everyones are in the end Etherchannel.

    I put here a reference guide of configuring Etherchannel in Cisco:

    http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.1/19ew/configuration/guide/channel.pdf

    To clear things up, vSphere does not support LACP (neither as mode active nor mode passive), but does support Static EtherChannels / Link Aggregation Groups (mode on). To use LACP requires a Nexus 1000v virtual switch. Make sure your distribution policy is set to ip-src-dst.



  • 5.  RE: Load balancing and Failover order

    Posted Jul 23, 2012 07:12 AM

    Thanks both of you for the clarification !