Juniper JN0-683 Exam Dumps - Actual Questions Answers

In this scenario, you want the border leaf device to advertise Type 5 EVPN routes to another border leaf in a different data center. Type 5 routes in EVPN are used to advertise IP prefixes, which means that for proper route advertisement, you need to configure the correct settings within the evpn hierarchy.

Step-by-Step Analysis:

Understanding EVPN Type 5 Routes:

EVPN Type 5 routes are used to advertise IP prefixes across EVPN instances, which allow different data centers or networks to exchange routing information effectively.

VRF Target Setting:

The vrf-target configuration is crucial because it defines the export and import policies for the VRF within the EVPN instance. For EVPN Type 5 routes to be advertised to other border leaf devices, the vrf-target needs to be correctly configured under the evpn hierarchy, not just within the routing instance.

Command to solve this:

move vrf-target target:65000:1 to evpn

Other Options:

Option B:Adding a VLAN configuration would not address the requirement to advertise Type 5 routes.

Option C:Adding VXLAN encapsulation may be necessary for other scenarios but does not directly address the Type 5 route advertisement.

Option D:Changing the route-distinguisher will differentiate routes but does not impact the advertisement of Type 5 routes to other data centers.

By moving the vrf-target to the evpn hierarchy, you enable the proper route advertisement, ensuring that the Type 5 routes for local networks are shared with other data center border leaf devices. This is aligned with best practices for multi-data center EVPN implementations, which emphasize the correct placement of routing policies within the EVPN configuration.

Step 1: Understand the Configuration in the Exhibit

The exhibit provides three configuration snippets from a leaf device (user@leaf#):

Policy Options:

user@leaf# show policy-options

policy-statement load-balance {

term 1 {

then {

load-balance per-packet;

}

}

}

A policy named load-balance is defined, which applies the load-balance per-packet action. In Juniper terminology, per-packet actually means per-flow load balancing (a common point of confusion). This policy is intended to enable load balancing across multiple paths.

Routing Options:

user@leaf# show routing-options

router-id 192.168.100.11;

autonomous-system 65100;

The router ID is set to 192.168.100.11, and the autonomous system (AS) number is 65100. There’s no mention of applying the load-balance policy here, which is a clue to the issue.

BGP Configuration:

user@leaf# show protocols

bgp {

group spine {

type external;

export direct;

local-as 65003;

multipath {

multiple-as;

}

neighbor 172.16.1.5 {

peer-as 65001;

}

neighbor 172.16.1.17 {

peer-as 65002;

}

}

}

BGP is configured with an external group spine, where the leaf device (local AS 65003) peers with spine devices (AS 65001 and 65002).

The multipath multiple-as statement is enabled, which allows BGP to install multiple paths for the same prefix in the routing table, even if the paths come from different AS numbers. This is a prerequisite for load balancing in a multi-AS environment like an IP fabric.

The export direct policy is applied, which likely exports directly connected routes to the spine devices.

Step 2: Identify the Problem

The issue is that traffic from the leaf to the spine devices is not being load-balanced, despite the presence of a load-balance policy and BGP multipath. For load balancing to work in this scenario:

BGP multipath ensures multiple paths are installed in the routing table.

The load-balance per-packet policy is meant to distribute traffic across those paths.

However, the load-balance policy is defined but not applied anywhere in the configuration shown. For load balancing to take effect, the policy must be applied in the correct context.

Step 3: Evaluate the Options

Let’s go through each option to determine the correct solution:

A. The load-balance policy must be applied to the forwarding table under the routing-options hierarchy.

In Junos, to enable load balancing across multiple paths for forwarding, the load-balance policy must be applied at the forwarding table level. This is done under the routing-options hierarchy using the forwarding-table export statement. For example:

set routing-options forwarding-table export load-balance

This ensures that the load-balancing policy is applied to the forwarding table, allowing traffic to be distributed across multiple equal-cost paths installed by BGP.

B. The multipath multiple-as configuration must be configured for each peer in the BGP spine group.

The multipath multiple-as statement is already configured under the spine group, and it applies to all neighbors in that group (172.16.1.5 and 172.16.1.17). There’s no need to configure it per peer, as the group-level configuration is sufficient. This option is incorrect because the required setting is already in place.

C. The load-balance policy must be applied as an export policy to your BGP.

Applying the load-balance policy as a BGP export policy (e.g., export load-balance under the BGP group) would affect the routes advertised to the spine devices. However, the load-balance per-packet action is a forwarding action, not a route advertisement action. Applying it as a BGP export policy would not achieve the desired load balancing for traffic forwarding and is incorrect.

D. The load-balance policy must have a from statement that matches on protocol bgp.

The load-balance policy currently applies the load-balance per-packet action unconditionally (no from statement). Adding a from protocol bgp condition would make the policy apply only to BGP routes, but this is unnecessary in this context. The policy needs to be applied to the forwarding table to affect traffic, not modified with a from statement. This option doesn’t address the core issue of applying the policy.

Step 4: Determine the Correct Answer

The key issue is that the load-balance policy is defined but not applied. For load balancing to work, it must be applied to the forwarding table under routing-options. This matchesOption A:

A. The load-balance policy must be applied to the forwarding table under the routing-options hierarchy.

Step 5: Provide Official Juniper Documentation Reference

Since I don’t have direct access to Juniper’s proprietary documents, I can provide an explanation based on standard Junos documentation practices and publicly available resources, such as the Juniper TechLibrary, which is the official source for Junos configuration guides.

In Juniper’s official documentation, specifically in theJunos OS Routing Protocols and Policies Configuration Guide, the process for enabling load balancing is described as follows:

Load Balancing in Junos: To enable per-flow load balancing across multiple paths, you must define a policy with the load-balance per-packet action and apply it to the forwarding table. The relevant configuration hierarchy is:

routing-options {

forwarding-table {

export ;

}

}

Explanation from Documentation: The load-balance per-packet action (which performs per-flow balancing) requires the policy to be applied at the forwarding-table level to influence how traffic is distributed across multiple paths in the forwarding table. Without this, even if BGP installs multiple paths (via multipath), the forwarding engine will not load-balance traffic.

This aligns with the JNCIP-DC exam objectives, which include understanding how to configure and troubleshoot load balancing in an IP fabric, such as applying policies for traffic distribution.

ï‚· 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.

ï‚· 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).

ï‚· 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.