Networking: VMkernel default gateway

[ndmuser]

Hi everyone,

Can I have service console port group, VMKernel port group, VM network port group connected to the same vSwitch connected to two physical nics? Both physical NICs are on the same physical subnet. I am not using any IP storage.

Do I need to assign defaul gateway to VMKernel port if VMkernel port, service console port, one VM group port are connected to the same IP subnet and two other VM port groups are connected to two different Ip subnets? Is it right that in my case default gateway for VMkernal port would be the same as for service console?

I have two ESX 3.5 servers and VC server 2.5 for about 1,5 year. Initailly there were ESX 3.0.1 and VC server 2. Reading the Server Configuration Guide for ESX 3.5, "VMKernel Networking Configuration" I noticed on page 33:

1. "NOTE: Set a default gateway for the port that you created. VirtualCenter 2 behaves

differently from VirtualCenter 1.x. You must use a valid IP address to configure the

VMkernel IP stack, not a dummy address."

2. "On the Routing tab, the service console and the VMkernel each need their own

gateway information. A gateway is needed if connectivity to machines not on

the same IP subnet as the service console or VMkernel."

I do not have default gateway set for my VMKernel port but VMotion is working OK...

Please advice if I need to add default gateway to my VMKernel port. Also the first question is of big importance too.

Thank you very much!

[VirtualNoitall]

"Please advice if I need to add default gateway to my VMKernel port. Also the first question is of big importance too."

This is not required if all your hosts Vmotion\VMKernel nics are on the same subnet\VLAN.

Hope that helps!

[ChrisMT]

You will still need to set the VMKernel's Default GW, it doesn't "assume" that it's using the same one that the console uses. And yes, you can have all those things on the same 2 physical adapters, setup as one vSwitch group.

If your concerned about VMKernel traffic getting out, you could create a VLAN, and set that traffic on it's own isolated VLAN.

Advanced example = VMotion traffic, on VMotion0 (VMKernel) is tagged for VLAN 8, but make sure that you also create another console port that is also on VLAN8 so that you can VMotion, if you have that need. Just remember to tag the physical switch ports as well for VLAN8 😃

[ChrisMT]

I've noticed that if you don't set the VMKernel Default Gateway, even if its on the same subnet, that VMotion won't work, at least this was true of 3.0.2.