Traffic-shaping policy

[tvmo]

Hello,

VC 2.5 ESX 3.5

I know that traffic shaping is applied and effective on the port group and that it effcts outbound network traffic only. What I can't get to grips with is the following:

1. Does traffic shaping effect traffic between VMs on the same port group, on the same vswitch, on the same host?

2. Does traffic shaping effect traffic between VMs on different port groups, on the same vswtich, on the same host?

3. Does traffic shaping effect traffic between VMs on different port groups, on different vswitches, on the same host?

4. Does traffic shaping effect traffic between VMs on different port groups, on different vswitches, on different hosts?

5. What does 'outbound' actually mean? Outbound from the port group?

Thanks

[AndreTheGiant]

Traffic shaping works only for output traffic of all the portgroup.

In vSphere (with DVS) can also work for inconming traffic.

Andre

[tvmo]

Thanks very much for the reply. So if I undertsand you the answer to my questions would be:

1. Does traffic shaping effect traffic between VMs on the same port group, on the same vswitch, on the same host? - NO

2. Does traffic shaping effect traffic between VMs on different port groups, on the same vswtich, on the same host? - YES

3. Does traffic shaping effect traffic between VMs on different port groups, on different vswitches, on the same host? - YES

4. Does traffic shaping effect traffic between VMs on different port groups, on different vswitches, on different hosts? - YES

Thanks again

[AndreTheGiant · Accepted solution]

1. Does traffic shaping effect traffic between VMs on the same port group, on the same vswitch, on the same host? - NO

Right

2. Does traffic shaping effect traffic between VMs on different port groups, on the same vswtich, on the same host? - YES

3. Does traffic shaping effect traffic between VMs on different port groups, on different vswitches, on the same host? - YES

4. Does traffic shaping effect traffic between VMs on different port groups, on different vswitches, on different hosts? - YES

Right (but only for outgoing traffic).

Andre

[tvmo]

Great thank Andre. Is there any VMware doc that outlines this?

[AndreTheGiant]

Is there any VMware doc that outlines this?

Check on ESX documentation.

For example page 53 of: http://www.vmware.com/pdf/vi3_35/esx_3/r35u2/vi3_35_25_u2_3_server_config.pdf

But there are just a few informations.

Andre

[tvmo]

Thanks Andre, I've read that doc. It's not great in defining exactly what 'outbound' traffic is.

Thanks again.

[AndreTheGiant]

It's not great in defining exactly what 'outbound' traffic is.

Unfortunately no.

You can find some generic concept on Linux documentation (traffic shaping is similar), for example: http://lartc.org/

Andre

[tvmo]

I've just completed a VMware VI3 mock exam. The following question came up:

Which statement describing internal-only virtual switches is true?

• Traffic shaping is not supported

• Used to access NFS and NAS datastores

• Requires 802.3ad link aggregation

• Ports are known as vswif

From your responses in this thread I would ay that none of them are right, as we discussed that traffic shaping affects outbound traffic from the port group. The correct answer, according to the mock exam, is the first one, i.e. not supported. So therefore traffic shaping must affect traffic oputbound from the virtual switch?

Am I missing something here?

Thanks.

[AndreTheGiant]

Traffic shaping is not supported

True: you need a outgoing physical interface

Used to access NFS and NAS datastores

False: it's impossible without an "external" access

Requires 802.3ad link aggregation

False: you do not have link at all

Ports are known as vswif

False: only Service Console port ar vswif interfaces.

Andre

[tvmo]

Thanks Andre,

Just to clarify the point in my mind, you are saying that traffic shaping:

1. Does not affect outbound traffic between VMs on separate port groups on the same internal-only vswitch.

2. Does affect outbound traffic between VMs on separate port gorups on the same vswitch associated with an uplink.

Cheers

[AndreTheGiant]

1. Does not affect outbound traffic between VMs on separate port groups on the same internal-only vswitch.

Yes, but if you have different portgroup maybe you have different network, and without a uplink they cannot spoke at all

2. Does affect outbound traffic between VMs on separate port gorups on the same vswitch associated with an uplink.

Yes

Andre

[tvmo]

OK, so the rule of network traffic between VMs on the same vswitch (no uplink), routing within the ESX host only applies if the VMs are on the same port group? If the VMs are on separate port groups, but on the same vswitch with an uplink the network traffic between them is routed via the uplink?

Cheers

[AndreTheGiant]

vSwitch are the same as layer2 switch: no routing.

VM can spoke internally only if they are on the same portgroup, or in the same broadcast domain on the same vSwitch.

Andre

[tvmo]

Thanks a lot Andre, that makes perfect sense.

Cheers