Most Recent Juniper JN0-683 Exam Questions & Answers

DHCP Behavior in Factory-Default Configuration:

Option B: In the factory-default configuration, Juniper switches are designed to send DHCP requests on all operational interfaces. This behavior ensures that the switch can obtain an IP address for management and further configuration from any available DHCP server.

Option D: The DHCP server can provide additional configuration parameters, including the required Junos version. This allows for automated provisioning and ensures that the switch is running the correct software version.

Conclusion:

Option B: Correct---The switch will use any operational interface to request an IP address via DHCP.

Option D: Correct---The DHCP server can specify Junos version requirements, enabling automated software management.

Understanding the Scenario:

In an EVPN-VXLAN environment, when using multi-homing in active/active scenarios, there's a risk that a multihomed server might receive duplicate copies of Broadcast, Unknown unicast, and Multicast (BUM) traffic. This is because multiple VTEPs might forward the same BUM traffic to the server.

EVPN Route Types:

Type 4 Route (Ethernet Segment Route): This route type is used to advertise the Ethernet Segment (ES) to which the device is connected. It is specifically used in multi-homing scenarios to signal the ES and its associated Ethernet Tag to all the remote VTEPs. The Type 4 route includes information that helps prevent BUM traffic duplication in active/active multi-homing by using a split-horizon mechanism, which ensures that traffic sent to a multihomed device does not get looped back.

The Type 4 route is crucial for ensuring that in a multi-homed setup, particularly in an active/active configuration, BUM traffic does not result in duplication at the server. The route helps coordinate which VTEP is responsible for forwarding the BUM traffic to the server, thereby preventing duplicate traffic.

Data Center Reference:

Type 4 routes are essential for managing multi-homing in EVPN to avoid the issues of BUM traffic duplication, which could otherwise lead to inefficiencies and potential network issues.

Understanding Bridged Overlay Architecture:

In a single-tenant data center using a bridged overlay architecture, virtual networks (VLANs) are typically isolated within the fabric, with traffic between these VLANs handled outside the fabric.

Communication Between Different Virtual Networks:

A . off-fabric using an external device: This is correct. In many bridged overlay architectures, communication between different virtual networks is handled off-fabric, often using an external router or firewall that connects the different VLANs. The fabric itself primarily provides Layer 2 connectivity within each VLAN, leaving inter-VLAN routing to be handled externally.

Data Center Reference:

This design is common in smaller or simpler data center environments where a single tenant does not require complex on-fabric routing and prefers to handle inter-VLAN routing through dedicated devices.

Understanding the Problem:

Host1 (10.1.1.1) is failing to communicate with Host2 (10.1.2.1) within an EVPN-VXLAN environment using ERB architecture.

Analysis of the Exhibit:

The provided output includes information from the show route forwarding-table matching command for IP 10.1.2.1. The next hop is shown as vtep.32769, which indicates that the traffic destined for 10.1.2.1 is being forwarded into the VXLAN tunnel with the correct VTEP (VXLAN Tunnel Endpoint).

Conclusion:

Option B: Correct---The traffic from Host1 is entering the VXLAN tunnel, as evidenced by the next hop pointing to a VTEP. However, the issue could lie elsewhere, possibly with the remote VTEP, routing configurations, or the receiving leaf/spine devices.

Redundant Gateways in EVPN-VXLAN:

In an EVPN-VXLAN environment, providing redundant gateway functionality typically involves the use of Anycast Gateway. This allows multiple PEs (Provider Edge devices) to use the same IP address and MAC address for the gateway, enabling seamless failover and redundancy without IP conflicts.

Conserving Address Space:

Using the same IP address across multiple PEs conserves address space because only one IP address is needed for the gateway function, regardless of the number of PEs. The shared MAC address ensures that ARP resolution and forwarding behavior are consistent across all the PEs.

Conclusion:

Option C: Correct---Using IRB interfaces with the same IP and MAC address across all PEs satisfies the need for redundancy while conserving address space.

Options A, B, and D introduce unnecessary complexity or do not fully utilize the efficient Anycast Gateway approach, which is best practice for conserving IP space and providing redundancy.