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m1xed0s
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Help me understand a little bit of vsphere networking...

I am doing a lab setup with the spare/old gears around office. It is fairly simple as diagram shown below.

The gateway and L2 switch in the diagram are illustration sample of production enterprise class devices. I have one HP server with two physical NICs and a SMB dumb switch to form the lab. The SMB HP branded dumb switch does do VLAN tagging/trunking but no spanning-tree and LACP capability. I have ports on SMB switch as Trunk connecting to both NICs and the NICs are active uplinks on ESXi host.

Initially I thought the connections between host and smb switch would cause a loop but when I get everything powered up, traffic flows...So does vsphere VSS do spanning-tree OR does it handle BPDU?

In my case, will both NIC1 and NIC2 be used for traffic forwarding actively? I use the default setting in teaming configuration inside vsphere.

What happens if I add a second HP server as ESXi and run VDS cross two ESXi hosts within vCenter. Also connect the second ESXi to the same SMB Switch with similar connection setup? Will VDS handle traffic differently? Again assuming I use the default setting inside teaming configuration.

test.jpg

What if I have four NICs on the host and two identical HP Branded DUMB SMB switches (non-stack)? I put two NICs (1&2) connecting to one switch and another two NICs(3&4) to the other. I would put four NICs as active uplinks and I assume that would cause issues potentially right?

If so, then should I put NIC1&2 as active and NIC3&4 as standby OR should I put NIC1&3 as active and NIC2&4 as standby? Still use "Route based on the originating port ID" under teaming.

Thanks,

/S

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daphnissov
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So does vsphere VSS do spanning-tree OR does it handle BPDU?

ESXi (not vSphere since that's a bundling of vCenter + ESXi) is not capable of forming loops as it handles its own packet flow there.

In my case, will both NIC1 and NIC2 be used for traffic forwarding actively? I use the default setting in teaming configuration inside vsphere.

You're probably using route based on originating port ID, which will have one vNIC select one physical uplink in the team. If you have multiple VMs running on this host, it is likely both vmnic uplinks are active simultaneously. This is correct operation.

What happens if I add a second HP server as ESXi and run VDS cross two ESXi hosts within vCenter. Also connect the second ESXi to the same SMB Switch with similar connection setup? Will VDS handle traffic differently?

By default it won't, however you could change that behavior by selecting other teaming policies which the vDS enables that the vSS does not. Presence of a vDS does not necessarily impact how the I/O plane works across hosts.

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daphnissov
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So does vsphere VSS do spanning-tree OR does it handle BPDU?

ESXi (not vSphere since that's a bundling of vCenter + ESXi) is not capable of forming loops as it handles its own packet flow there.

In my case, will both NIC1 and NIC2 be used for traffic forwarding actively? I use the default setting in teaming configuration inside vsphere.

You're probably using route based on originating port ID, which will have one vNIC select one physical uplink in the team. If you have multiple VMs running on this host, it is likely both vmnic uplinks are active simultaneously. This is correct operation.

What happens if I add a second HP server as ESXi and run VDS cross two ESXi hosts within vCenter. Also connect the second ESXi to the same SMB Switch with similar connection setup? Will VDS handle traffic differently?

By default it won't, however you could change that behavior by selecting other teaming policies which the vDS enables that the vSS does not. Presence of a vDS does not necessarily impact how the I/O plane works across hosts.

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m1xed0s
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Thanks, so VSS or VDS does not participate spanning-tree. I guess it will just be transparent for BPDU then?

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daphnissov
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m1xed0s
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Cool! Another question: what if I have four NICs on the server and two identical HP Branded DUMB SMB switches (non-stack)? I put two NICs (1&2) connecting to one switch and another two NICs(3&4) to the other. I would put four NICs as active uplinks and I assume that would cause issues potentially right? If so, should I put NIC1&2 as active and NIC3&4 as standby OR should I put NIC1&3 as active and NIC2&4 as standby? Still use "Route based on the originating port ID" under teaming.

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daphnissov
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No, that shouldn't cause issues from an ESXi perspective, although you're always opening yourself up for issues when you use cheap L2 devices. When using route based on originating virtual port ID, ESXi will select one physical uplink (vmnic) from the team to dedicate to a VM (per NIC). So, from a VM's perspective, it's always sending and receiving traffic through a single uplink.

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