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EX4550 port configuration for VMWare ESXi to support many VLANs

‎10-29-2018 01:46 PM

I hope this is the right forum to ask this.

 

I have 20 ESXi 6.5 hosts connected to our EX4550 virtual chassis (2 switches).  We have some performance issues so I'm trying to validate my configuration before chasing other wild geese.

 

Each ESXi host has 2 x 10 GbE ports.  Each port is connected to one of the two switches in the virtual chassis.  (See attached image) The desire was to have the switch be able to handle any traffic between any ESXi host on any VLAN where the VLAN is tagged within the VMWare vCenter vmkernel configuration.  Each port on the switch is configured identically (see below) as a layer-2 uplink port role.

 

While this works to a degree, moving VM's between hosts is very slow and we get intermittent connection issues (ESX management connections lost, vMotion failing, etc.) I was wondering if maybe it was routing the VLAN traffic out of the switch to the gateway MDF and back instead of staying local.   This led me to start looking into Routed VLAN Interface (RVI), but I don't fully grasp when this might be needed or how to configure it for all the ports.  

 

I'm open to any suggestions on how to better achieve the desired result.  I'm definitely still learning.

 

Thanks!

 

 

xe-0/0/NN {
   apply-macro juniper-port-profile {
      "Layer 2 Uplink";
   }
   mtu 1514;
   ether-options {
      auto-negotiation;
      flow-control;
      link-mode full-duplex;
      speed {
         10g;
      }
   }
   unit 0 {
      family ethernet-switching {
         port-mode trunk;
         vlan {
            members [ 1 110 124 ];
         }
         native-vlan-id Native;
      }
   }
}

 

 Network.png

 

4 REPLIES 4
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Re: EX4550 port configuration for VMWare ESXi to support many VLANs

[ Edited ]
‎10-30-2018 02:43 AM

I think you need mtu of 1518 for 8021.q tagged interfaces.

So either change it to 1518 or just remove the mtu statement.

Another option is to create group with MTU of, lets say 9000, and apply it to all interfaces:

set groups SET-MTU-9000 interfaces <*> mtu 9000
set interfaces apply-groups SET-MTU-9000

There is nothing bad in having l2 mtu set to maximum 🙂 

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Re: EX4550 port configuration for VMWare ESXi to support many VLANs

‎10-30-2018 07:45 AM

If you enable Jumbo frame at the Juniper, You need to make configuration changes on all environment(Guest Network driver - OS, VMware Virtual Switch, Physical NICs on hosts and all intermediate hops/routers/switches ).

 

Also, I recommend you to check out the "Performance Best Practice for Vmware" document.



If this worked for you please flag my post as an "Accepted Solution" so others can benefit.
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Re: EX4550 port configuration for VMWare ESXi to support many VLANs

‎10-30-2018 09:02 AM

No, you dont have to change mtu on all esxi hosts. The main goal is that your actual MTU should be lower or equal  MTU on the path. If frame is biger than path MTU than it will be dropped. If its lower - it wil go through.

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Re: EX4550 port configuration for VMWare ESXi to support many VLANs

‎10-30-2018 11:54 AM

This is not a must, it is necessary for better performance.

 

https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/techpaper/performance/Perf_Best_Pr...



If this worked for you please flag my post as an "Accepted Solution" so others can benefit.
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