Exam CCSP topic 1 question 66 discussion

I think this is purely wrong or poor verbiage for the questions itself. VLANs can span DCs in general ,but a single VLAN wont! The technology that is used to do that is actually VxLAN!

ANS A. A. They are not restricted to the same data center or the same racks. But the verbiage in Statement for Correct answer contradicts answer A.

A. They are not restricted to the same data center or the same racks.

VLANs, or Virtual Local Area Networks, are a way of segmenting a physical network into logical sub-networks. VLANs are typically used to isolate different groups of devices or applications on a network, such as to provide security or performance benefits. VLANs are not restricted to the same data center or the same racks, meaning that they can span multiple data centers or racks within a network. Instead, VLANs are typically defined based on logical criteria, such as the type of device or application being used, or the VLAN ID assigned to the device or application.

Correct answer is B. You cannot stretch a VLAN over WAN, the moment you do, you're using other technologies such as PW, vXLAN, etc. to transport your Layer2 vlan....but VLANs by themselves ca only span within a datacentre or campus.

Plenty of people use layer 2 vlans across datacentres in a stretched storage and/or hypervisor cluster active/active mode. it's a high availability strategy (as opposed to DR)

A is correct, even though it is a shitty practice and I would say B is highly preferable.

A stretched VLAN is a VLAN that spans multiple physical data centers. https://download3.vmware.com/vcat/vmw-vcloud-architecture-toolkit-spv1-webworks/Hybridity/Architecting%20a%20Hybrid%20Mobility%20Strategy/Architecting%20a%20Hybrid%20Mobility%20Strategy.2.14.html#:~:text=A%20stretched%20VLAN%20is%20a,complex%20considerations%20from%20the%20environment.

Looks like Answer is correct. VLAN could be from different datacenter as well.

Given answer is incorrect. Correct Answer is B. VLANs are always restricted to the same data center. It can be spread across to multiple racks in the same datacenter. For example when a packet wants to leave a datacenter it has to use a WAN connection. And VLAN name itself Virual local area network. It cannot travel through WAN.