VLAN: Tagged or Untagged frames to Servers?

[Redfox1]

Simple question:

What benefit is there to configure a W2K server's NIC card to support VLANs (i.e. configure the switch to send 802.1Q TAGGED frames to the server)?

(Assume NIC cards are for HP Proliant type machines. Assume Managed switch is an HP ProCurve for example.)

Example Configuration:

10.1.1.0/24 -> Managed Switch (ports 1-6: VLAN ID: 1)
10.1.2.0/24 -> Managed Switch (ports 6-12: VLAN ID: 2)

The 10.1.1.0 network would keep all the wiring center connections to switches which in turn are connected PCs & Print Servers etc.

The 10.1.2.0 network would keep all the servers (directly connected to the Managed Switch)

The Managed Swich has built in support for basic routing. I.e. It doesn't need an extra router to send packets between the two sample subnets...

 

[chieftan999]

This would be classed as ingress filtering. This is rarely used. The frame would only be 802.1q tagged if it was traversing a trunk.

Normally you would configure the switch for this and not the NIC on the server. The switch will know which port to channel the packets through.

 

[jimbopalmer]

If routing were 'expensive', there could be benefit to having an IP address in each subnet, so fewer packets needed routing, tagged VLANs would be a clean way of doing that. In your network, it does not look like that is the case.

If the bandwidth to the router was constrained, same story. But if the router is in the switch, it has the switch fabric's bandwidth.

I confess I usually choose to let my network gear network, and let my servers serve, I hate to give up CPU cycles to stuff the switch can do in hardware.

I tried to remain child-like, all I acheived was childish.

 

[Redfox1]

Thanks for your answers.

From what I've read on other sites it seams like, IF the switch would send TAGGED frames to the server's NIC cards then wouldn't the server's need an IP address PER VLAN interface defined in it's properties? (otherwise it wouldn't be able to answer packets destined to another VLAN without a router involved...)

The ONLY benefit I can see in this is that the Switch would not have to ROUTE any packets since the "servers" are essentially considered to be in the same VLAN (i.e. subnet.)

Isn't this essentially the same as having multiple NIC cards in a server attached to multiple (dumb) switches which represent subnets???

Overall, the benefit I see with using the HP ProCurve 2626 is that it's a ROUTING Switch, i.e. it routes everything at 9.9Gbs speeds!!! (or close to it... per the specs) This removes the need to send TAGGED frames to the Servers since the switch can route to these and therefore reduce the broadcasts; which is ultimately (one of the things) I want to do!

Does this sound right?