Juniper JN0-649 Online Practice Questions and Exam Preparation

Juniper JN0-649 Online Questions & Answers

• Question 61:

  You are troubleshooting an EVPN-VXLAN IP fabric and observe the loop shown in the exhibit. Which two steps would you take to further troubleshoot this problem? (Choose two.)

  

  A. Verify that the same ESI is configured on the link from thehost and that it matches the source.
  B. Issue the show route table bgp.evpn.0 command on Leaf2 and verify that Type 4 routes are present.
  C. Issue the show route table bgp.evpn.0 command on Leaf2 and verify that Type 3 routes are present.
  D. Verify thatthe same ESI is configured on the two links from the source.
  B. Issue the show route table bgp.evpn.0 command on Leaf2 and verify that Type 4 routes are present.
  C. Issue the show route table bgp.evpn.0 command on Leaf2 and verify that Type 3 routes are present.

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  Explanation/Reference:

  Type 2 route, MAC with IP advertisement route--Type 2 routes are per-VLAN routes, so only PEs that are part of a VNI need these routes. EVPN allows an end host's IP and MAC addresses to be advertised within the EVPN Network Layer reachability information (NLRI). This allows for control plane learning of ESI MAC addresses. Because there are many Type 2 routes, a separate route-target auto-derived per VNI helps to confine their propagation. This route type is supported by all EVPN switches and routers. Type 5 route, IP prefix Route--An IP prefix route provides encoding for inter-subnet forwarding. In the control plane, EVPN Type 5 routes are used to advertise IP prefixes for inter-subnet connectivity across data centers. To reach a tenant using connectivity provided by the EVPN Type 5 IP prefix route, data packets are sent as Layer 2 Ethernet frames encapsulated in the VXLAN header over the IP network across the data centers.

• Question 62:

  Referring to the exhibit, you haveplaced the cos multifield classifier on all edge interfaces and configured the relevant CoS parameters. In this scenario, which two statements are correct? (Choose two.)

  A. SSH traffic using the default port will be placed in the af forwarding classand accepted.
  B. SSH traffic using the default port will be placed in the best-effort forwarding class and accepted.
  C. UDP traffic using the 16000 port will be placed in the voice forwarding class and accepted.
  D. UDP traffic using the 16000 port will beplaced in the best-effort forwarding class and accepted.
  A. SSH traffic using the default port will be placed in the af forwarding classand accepted.
  C. UDP traffic using the 16000 port will be placed in the voice forwarding class and accepted.

• Question 63:

  Your enterprise network uses routing instances to support multitenancy. Your Junos devices use BGP to peer to multiple BGP devices. You must ensure that load balancing is achieved within the routing instance. Which two statements would accomplish this task? (Choose two.)

  A. Configure the multipath option at the [edit protocols bgp group neighbor] hierarchy.
  B. Configure the multipath option at the [edit protocols bgp group] hierarchy.
  C. Configure a load-balance per-packet policy and apply it at the [edit routing-options forwarding-table] hierarchy.
  D. Configure the multipath option at the [edit routing-instances routing-options] hierarchy.
  B. Configure the multipath option at the [edit protocols bgp group] hierarchy.
  C. Configure a load-balance per-packet policy and apply it at the [edit routing-options forwarding-table] hierarchy.

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  Explanation/Reference:

  Fortunately, the Juniper Networks BGP implementation supports the notion of a bandwidth community. This extended community encodes the bandwidth of a given next hop, and when combined with multipath, the load-balancing algorithm distributes flows across the set of next hops proportional to their relative bandwidths. Put another way, if you have a 10-Mbps and a 1-Mbps next hop, on average nine flows will map to the high-speed next hop for every one that uses the low speed.

  Use of BGP bandwidth community is supported only with per-packet load balancing.

  The configuration task has two parts:

  Configure the external BGP (EBGP) peering sessions, enable multipath, and define an import policy to tag routes with a bandwidth community that reflects link speed.

  Enable per-packet (really per-flow) load balancing for optimal distribution of traffic.

  https://www.juniper.net/documentation/us/en/software/junos/bgp/topics/topic-map/load-balancing-bgp-session.html

• Question 64:

  What are two similarities between OSPFv2 and OSPFv3? (Choose two.)

  A. virtual links
  B. support for multiple instances per link
  C. 32-bit router ID
  D. protocol processing per link, not persubnet
  A. virtual links
  C. 32-bit router ID

• Question 65:

  You are asked to configure 802.1X on your access ports to allow only a single device to authenticate. In this scenario, which configuration would you use?

  A. single supplicant mode
  B. multiple supplicant mode
  C. single-secure supplicant mode
  D. MAC authentication mode
  C. single-secure supplicant mode

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  Explanation/Reference:

  Single supplicant mode authenticates only the first end device that connects to an authenticator port. All other end devices connecting to the authenticator port after the first has connected successfully, whether they are 802.1X-enabled or not, are permitted access to the port without further authentication. If the first authenticated end device logs out, all other end devices are locked out until an end device authenticates. Single-secure supplicant mode authenticates only one end device to connect to an authenticator port. No other end device can connect to the authenticator port until the first logs out.