Inter-vlan routing in the VDS without physical router

[kc987654321]

I have one VDS with many VLANS and have no physical routers connected to it.  How can I configure this dvSwitch such that the traffic can go from one vlan to another vlan ? (eg VLAN1 and VLAN2 can talk to each other) .

Actually , I want to deploy a NetScaler VPX as the L3 router to route the traffic between the VLANs . For example , the traffic can go in the following directions:

• From VLAN1 to NetScaler
• From NetScaler to VLAN1
• From NetScaler to VLAN2

But cannot go from VLAN2 to NetScaler.

It will be nice if someone can give me a direction. Thanks so much

[MKguy]

The vDS has no out of the box routing capabilities. You will need a VM with a vNIC attached to each VLAN/port group that does the routing, like your netscaler VPX appliance or one of many other such networking appliances. You can also install a Linux box the same way to handle the routing or handling ACLs via iptables.

Please refer to the respective virtual appliance documentation for configuration details of their respective solutions.

[kc987654321]

You will need a VM with a vNIC attached to each VLAN/port group that does the routing, like your netscaler VPX appliance or one of many other such networking appliances.

A vNIC in a VM can only attach to one VLAN . So , does it mean that if I have 50 VLANS  , the networking appliances that do the routing will have 50 vNICs attached? Please correct me if I am wrong.

[MKguy]

A vNIC in a VM can only attach to one VLAN. So , does it mean that if I have 50 VLANS  , the networking appliances that do the routing will have 50 vNICs attached?

To be precise, a vNIC of a VM can only attach to one port group. This statement is only true if you run one VLAN per interface. (btw the maximum supported number of vNICs in a VM is 10)

The distributed vSwitch however can trunk multiple specific VLANs on a single port group (set Type to VLAN trunking) so that you could run a single VM vNIC with 50 VLANs at once. Like in the physical world when you trunk multiple VLANs on one server port, the VM's guest OS/software needs to be configured to take care of the 802.1q VLAN tag handling accordingly in this case.

In VMware terms VLAN tagging inside the guest this is usually referred to as "virtual guest tagging" (VGT), see:

VMware KB: Sample configuration of virtual machine VLAN Tagging (VGT Mode) in ESX

On a standard vSwitch you can use a port group with VLAN ID 4095 to trunk all available VLANs to this port group. See:

VMware KB: Configuring promiscuous mode on a virtual switch or portgroup

VLAN ID 4095 in VMware | virtualbrigade

[kc987654321]

Like in the physical world when you trunk multiple VLANs on one server port, the VM's guest OS/software needs to be configured to take care of the 802.1q VLAN tag handling accordingly in this case.

In VMware terms VLAN tagging inside the guest this is usually referred to as "virtual guest tagging" (VGT), see:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1004252VMware KB: Sample configuration of virtual machine VLAN Tagging (VGT Mode) in ESX

Thanks for the direction . So does this idea of VGT is the same as this link (which is about associating an IP Subnet with a NetScaler Interface by Using VLANs) ?

[MKguy]

I'm not a netscaler expert but yeah, this seems exactly the thing you need to do. You will have to select the "tag" checkbox for each VLAN interface.