5.2 Demonstrate Understanding of Routing and Forwarding Issue Resolution SD-WAN-ENGINEER Practice Questions (Page 3)

Questions 11–15

1. 11expert · hard

   An SD-WAN has two paths between a branch and the data center: Path A (MPLS, SLA 20ms, 50Mbps) and Path B (Internet, SLA 150ms, 500Mbps). A policy is configured to send 'video conferencing' traffic over the path with the best SLA. You notice that video traffic is using Path A, but the link is congested, causing the video to stutter. Path B is underutilized. The SLA on Path A is still 20ms, but the jitter is 30ms. What is the most likely reason the SD-WAN is not using Path B?

   • AThe path selection policy does not include jitter as a metric, so Path A is still considered the best SLA.
   • BPath A is the only path with a route to the data center for video traffic.
   • CThe video conferencing application is not being correctly identified by the SD-WAN.
   • DPath B is not meeting its SLA, so it is not eligible for selection.
   Reveal Solution Discussion Select an answer first
2. 12expert · hard

   An organization has a hub-and-spoke SD-WAN topology. A spoke site has two links: Link A (SLA 100ms, 100Mbps) and Link B (SLA 200ms, 1Gbps). A policy is configured to send 'mission-critical' traffic over the path with the best SLA. You observe that mission-critical traffic is consistently using Link A, but the link is congested and causing packet loss. Link B is underutilized. The SLA on Link A is still 100ms, but loss is now 2%. What should you do to resolve this?

   • AReduce the bandwidth on Link A to force the SD-WAN to load-balance traffic across both links.
   • BManually steer all mission-critical traffic to Link B using a static route.
   • CIncrease the SLA threshold for Link A to 80ms so it fails SLA and traffic fails over to Link B.
   • DModify the path selection policy to include a loss threshold, so Link A is deprioritized when loss exceeds a set value.
   Reveal Solution Discussion Select an answer first
4. 13application · medium

   A branch site is advertising a local subnet 192.168.1.0/24 to the hub. The hub is also receiving the same subnet from another branch. Users at the first branch report that they cannot reach the second branch's subnet. The hub's routing table shows two routes to 192.168.1.0/24, one from each branch. What is the most likely cause of the issue?

   • AThe tunnel between the two branches is down, so they cannot communicate directly.
   • BThe two branches are using overlapping subnets, causing a routing conflict at the hub.
   • CThe first branch's route is being filtered by the hub, so it is not advertised to the second branch.
   • DThe hub is load-balancing traffic between the two branches, causing intermittent connectivity.
   Reveal Solution Discussion Select an answer first
5. 14expert · hard

   A new branch is added to an SD-WAN fabric. The branch has a single WAN link. The hub advertises a default route and specific prefixes to the branch. The branch is configured to advertise its local subnet to the hub. After the branch is connected, users at the branch can reach the internet but cannot reach the data center's 10.10.0.0/16 subnet. The hub's routing table shows the 10.10.0.0/16 route, and the branch's routing table shows a route to 10.10.0.0/16 via the tunnel. What is the most likely cause of the issue?

   • AThe hub is not advertising the 10.10.0.0/16 route to the branch because of a route policy.
   • BThe branch's local subnet is overlapping with the data center's subnet, causing a routing conflict.
   • CThe branch's firewall is blocking traffic to 10.10.0.0/16 because the zone is not configured for inter-zone traffic.
   • DThe tunnel is up but the encapsulation is misconfigured, so packets are being dropped.
   Reveal Solution Discussion Select an answer first
6. 15application · medium

   Users at a branch report that they cannot reach a specific server at the data center, but they can reach other servers. You check the SD-WAN appliance and see that the tunnel is up, and the routing table has a route to the server's subnet. You also see that the packet count on the tunnel is increasing. What is the next most logical step in your troubleshooting methodology?

   • ACheck the data center's firewall logs to see if the server's traffic is being blocked.
   • BReboot the SD-WAN appliance to clear any potential forwarding table corruption.
   • CVerify the local LAN interface is up and has the correct VLAN configuration for the server's subnet.
   • DChange the tunnel encapsulation from IPsec to GRE to rule out encapsulation issues.
   Reveal Solution Discussion Select an answer first