Juniper Exam JN0-683 Topic 6 Question 25 Discussion

Understanding VXLAN Tunneling:

VXLAN (Virtual Extensible LAN) is a network virtualization technology that addresses the scalability issues associated with traditional VLANs. VXLAN encapsulates Ethernet frames in UDP, allowing Layer 2 connectivity to extend across Layer 3 networks.

Each VXLAN network is identified by a unique VXLAN Network Identifier (VNI). In this exhibit, we have two VNIs, 5100 and 5200, assigned to the VXLAN tunnels between leaf1 and leaf2.

Network Setup Details:

Leaf1: Connected to Server1 with VLAN ID 100 and associated with VNI 5100.

Leaf2: Connected to Server2 with VLAN ID 200 and associated with VNI 5200.

Spine: Acts as the interconnect between leaf switches.

Traffic Flow Analysis:

When traffic is sent from Server1 to Server2, it is initially tagged with VLAN ID 100 on leaf1.

The traffic is encapsulated into a VXLAN packet with VNI 5100 on leaf1.

The packet is then sent across the network (via the spine) to leaf2.

On leaf2, the VXLAN header is removed, and the original Ethernet frame is decapsulated.

Leaf2 will then associate this traffic with VLAN ID 200 before forwarding it to Server2.

Correct Interpretation of the Exhibit:

The traffic originating from Server1, which is tagged with VLAN ID 100, will be encapsulated into VXLAN and transmitted to leaf2.

Upon arrival at leaf2, it will be decapsulated, and since it is associated with VNI 5200 on leaf2, the traffic will be retagged with VLAN ID 200.

Therefore, the traffic will reach Server2 tagged with VLAN ID 200, which matches the network configuration shown in the exhibit.

Data Center Reference:

This configuration is typical in data centers using VXLAN for network virtualization. It allows isolated Layer 2 segments (VLANs) to be stretched across Layer 3 boundaries while maintaining distinct VLAN IDs at each site.

This approach is efficient for scaling large data center networks while avoiding VLAN ID exhaustion and enabling easier segmentation.

In summary, the correct behavior, as per the exhibit and the detailed explanation, is that traffic sent from Server1 will be tagged with VLAN ID 200 when it reaches Server2 via leaf2. This ensures proper traffic segmentation and handling across the VXLAN-enabled data center network.