Newby needs question answered around VMWare Networking

AudleyTravel used Ask the Experts™
Good morning experts, I am new to VMWare and SAN technologies and need to set up a few VMWare hosts in a cluster. My question lies around the best use of the 8 adapters in each of 3 hosts. We will be using HA in the cluster and will be attaching to a NetApp SAN via software iSCSI. I have read the VMWare iSCSI SAN Configuration guide but it doesn't take into consideration other networking needs.

My thinking is as follows:
Single adapter and vswitch for VMNetwork
Single adapter and vswitch for Management Network
Single adapter and vswitch for VMotion Network
Two adapters and vswitch for iSCSI Network
Three adapters and vswitch for corp network access

I would love your thought on the proposal.

Thank you
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
You haven't said what the underlying network infrastructure is for your environment.

I would suggest that you VLAN everything to make sure your networks are segmented correctly.

[quote]Single adapter and vswitch for VMNetwork[end quote]
[quote]Three adapters and vswitch for corp network access[end quote]

Unless you have something else in mind for your VMNetwork, you could  collapse these together and use four ports for all your virtual machines and corporate LAN access.


jakethecatuk, thanks for your reply and be gentile, as I said, I'm new to all of this.

The underlying network is a singe gigabit network on a single subnet. What VMWare services need to be segmented out to networks other than my corp network? I know the VMotion network wants to be on a separate segment but what about the others? I assume they are all happy on the same subnet as the rest?

you can leave everything on the same subnet, but you will be pumping a shed load of data around the same subnet and you MAY find that performance will be impacted.

what sort of network switches do you have and do they support VLAN's?

At home, I have two VM servers and an iSCSI SAN.  I have split my network out as follows: -

VLAN 1 - all normal traffic (workstations, fileserver, AD, exchange etc)
VLAN 2 - DMZ for websites and internet facing servers
VLAN10 - internet connection
VLAN20 - vMotion
VLAN21 - VM fault tolerance

For example, iSCSI.  If the iSCSI network is on your main backbone, someone could quite easily point their client at the iSCSI servers and try and map an iSCSI drive (ok - this can be prevented by using CHAP etc - but you get the general idea)

The main advantage of splitting them out is to keep traffic separate and if your switches support VLAN's, give it consideration.

You will also have more IP's to play around with.


My question lies more around configuring the network adapters on the hosts of the VMWare cluster. Lets just say for now that I cannot use VLANs. What would your recomentation be for allocating the 8 netwrok adapters in each host, given I am using iSCSI and VMotion?

Dedicated adatpter (vswitch) for VMWare Management
Dedicated adapter (vswitch) for VMotion
two teamed adapters (vswitch) for iSCSI traffic
four teamed adapters (vswitch) for LAN and VMNetwork traffic

that will work ok

you will need to give IP addresses to your VMware server, one for vMotion, one for iSCSI (even though you have two adapters).
Paul SolovyovskySenior IT Advisor
Top Expert 2008

I would recommend the following

two  adatpter (vswitch) for VMWare Management
two adapter (vswitch) for VMotion
two teamed adapters (vswitch) for iSCSI traffic
two  teamed adapters (vswitch) for LAN and VMNetwork traffic

I would also recommend a separate VLAN or physical switch for iSCSI, you don't want to have LAN and SAN traffic on the same subnet.  Sice the iSCSI traffic doesn't have to route a standalone switch (or two) would be your best best.

Keep in mind that you have to setup Multipathing to your iSCSI SAN for it to use more than a single network connection since the connection is session based you could have 4 connections but only 2 or 4 connections but only one of them would be used unless for failover.  2 port should be enough to start as well as for your LAN traffic.

Top Expert 2009
Feel free to express your opinion, but I don't think you need two adapters for Vmotion. You don't use Vmotion on daily basis and if you do, one private connection is good. For VMware Management, you can have two adapters since you may access to VC all the time. So here is the config I suggest:

two adatpters (vswitch) for VMWare Management
Dedicated adapter (vswitch) for VMotion
two teamed adapters (vswitch) for iSCSI traffic
three teamed adapters (vswitch) for LAN and VMNetwork traffic

Here is a very good document for you to follow:


Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial