Question 1

You are configuring a BGP signaled Layer 2 VPN across your MPLS enabled core network. In this scenario, which statement is correct?

Accepted Answer

BGP signaled Layer 2 VPN is a type of VPN that uses BGP to distribute VPN labels and information for Layer 2 connectivity between sites over an MPLS network.
BGP signaled Layer 2 VPN requires the support of the l2vpn NLRI on all core BGP devices1. The l2vpn NLRI is a new address family that carries Layer 2 VPN
information such as the VPN identifier, the attachment circuit identifier, and the route distinguisher. The l2vpn NLRI is used for both auto-discovery and signaling of
Layer 2 VPNs2. In this scenario, we are configuring a BGP signaled Layer 2 VPN across an MPLS enabled core network.
Therefore, we need to ensure that all core BGP devices support the l2vpn NLRI. References: 1: https://www.juniper.net/documentation/us/en/software/junos/vpnl2/topics/concept/vpn-layer-2-overview.html 2: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mp_l2_vpns/configuration/xe-16/mp-l2-vpns-xe-16-book/vpls-bgpsignaling-l2vpn- inter-as-option-a.html

Question 2

Which two statements describe PIM-SM? (Choose two)

Accepted Answer

PIM sparse mode (PIM-SM) is a multicast routing protocol that uses a pull model to deliver multicast traffic. In PIM-SM, routers with receivers send join messages
to their upstream neighbors toward a rendezvous point (RP) or a source-specific tree (SPT). The RP or SPT acts as the root of a shared distribution tree for a
multicast group. Traffic is only forwarded to routers that request to join the distribution tree by sending join messages. PIM-SM does not flood traffic to all routers or
prune routers without receivers, as PIM dense mode does.

Question 3

Which three mechanisms are used by Junos platforms to evaluate incoming traffic for CoS purposes? (Choose three )

Accepted Answer

Junos platforms use different mechanisms to evaluate incoming traffic for CoS purposes, such as:
? Behavior aggregate classifiers: These classifiers use a single field in a packet header to classify traffic into different forwarding classes and loss priorities based
on predefined or user-defined values.
? Fixed classifiers: These classifiers use a fixed field in a packet header to classify traffic into different forwarding classes and loss priorities based on predefined
values.
? Multifield classifiers: These classifiers use multiple fields in a packet header to classify traffic into different forwarding classes and loss priorities based on userdefined values and filters.
Rewrite rules and traffic shapers are not used to evaluate incoming traffic for CoS purposes, but rather to modify or shape outgoing traffic based on CoS policies.

Question 4

Exhibit

(65 New Questions)
Referring to the exhibit, which two statements are true? (Choose two.)

Accepted Answer

This is an EVPN Type-2 route, also called a MAC/IP advertisement route, that is used to advertise host IP and MAC address information to other VTEPs in an
EVPN network. The route type field in the EVPN NLRI has a value of 2, indicating a Type-2 route. The device advertising this route into EVPN is 192.168.101.5,
which is the IP address of the VTEP that learned the host information from the local CE device. This IP address is carried in the MPLS label field of the route as
part of the VXLAN encapsulation.

Question 5

Exhibit

(65 New Questions)
You have MAC addresses moving in your EVPN environment
Referring to the exhibit, which two statements are correct about the sequence number? (Choose two)

Accepted Answer

The sequence number is a field in the MAC mobility extended community that is used to resolve conflicting MAC address ownership claims and to help the local
PE to identify the latest advertisement. The sequence number is incremented by one for every MAC address mobility event, such as when a host moves from one
Ethernet segment to another segment in the EVPN network. The PE device that receives multiple MAC advertisements for the same MAC address chooses the
one with the highest sequence number as the most recent and valid advertisement.

Question 6

Which statement is true regarding BGP FlowSpec?

Accepted Answer

BGP FlowSpec is a feature that extends the Border Gateway Protocol (BGP) to enable routers to exchange traffic flow specifications, allowing for more precise
control of network traffic. The BGP FlowSpec feature enables routers to advertise and receive information about specific flows in the network, such as those
originating from a particular source or destined for a particular destination. Routers can then use this information to construct traffic filters that allow or deny
packets of a certain type, rate limit flows, or perform other actions1. BGP FlowSpec can also help in filtering traffic and taking action against distributed denial of
service (DDoS) attacks by dropping the DDoS traffic or diverting it to an analyzer2. BGP FlowSpec rules are internally converted to equivalent Cisco Common
Classification Policy Language (C3PL) representing corresponding match and action parameters2. Therefore, BGP FlowSpec uses dynamically created routing
policies to protect a network from denial-of-service attacks.
References: 1: https://www.networkingsignal.com/what-is-bgp-flowspec/ 2: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-16/irgxe-16-book/bgp-flowspec-route-reflector-support.html

Question 7

Which two statements about IS-IS are correct? (Choose two.)

Accepted Answer

IS-IS is an interior gateway protocol that uses link-state routing to exchange routing information among routers within a single autonomous system. IS-IS uses two
types of packets to synchronize link-state databases among routers: Link State Packets (LSPs) and Partial Sequence Number Packets (PSNPs). LSPs contain
information about the state and cost of links in the network, and are flooded periodically throughout the network. PSNPs are used to acknowledge receipt of LSPs
and request retransmission of missing or corrupted LSPs. PSNPs contain only descriptions of LSPs, such as their sequence numbers and checksums3. IS-IS also
uses another type of packet called Complete Sequence Number Packets (CSNPs), which are used to summarize the entire link-state database at regular intervals
or when a new adjacency is formed. CSNPs are flooded periodically throughout the network and contain only descriptions of LSPs4. Therefore, PSNPs contain
only descriptions of LSPs and CSNPs are flooded periodically. References: 3: https://www.juniper.net/documentation/us/en/software/junos/routingpolicy/topics/concept/routing-policy-is-is-partial-sequence-number-packet-psnp.html 4: https://www.juniper.net/documentation/us/en/software/junos/routingpolicy/topics/concept/routing-policy-is-is-complete-sequence-number-packet-csnp.html

Question 8

In IS-IS, which two statements are correct about the designated intermediate system (DIS) on a multi-access network segment? (Choose two)

Accepted Answer

In IS-IS, a designated intermediate system (DIS) is a router that is elected on a multi-access network segment (such as Ethernet) to perform some functions on
behalf of other routers on the same segment. A DIS is responsible for sending network link-state advertisements (LSPs), which describe all the routers attached to
the network. These LSPs are flooded throughout a single area. A DIS also generates pseudonode LSPs, which represent the multi-access network as a single

(65 New Questions)
node in the link-state database. A DIS election is based on the priority value configured on each router’s interface connected to the multi-access network. The
priority value ranges from 0 to 127, with higher values indicating higher priority. The router with the highest priority becomes the DIS for the area (Level 1, Level 2,
or both). If routers have the same priority, then the router with the highest MAC address is elected as the DIS. By default, routers have a priority value of 64. On a
multi-access network, each router only forms an adjacency to the DIS, not to every other router on the segment. This reduces the amount of hello packets and LSP

Question 9

Exhibit
Referring to the exhibit, you must provide Internet access for VPN-A using CE-1 as the hub CE.
Which two statements are correct in this situation? (Choose two.)

Accepted Answer

To provide Internet access for VPN-A using CE-1 as the hub CE, you need to do the following:
? You must use RIB groups to leak routes between the inet.0 and vpn-a.inet.0 tables on PE-1 and CE-1. RIB groups are routing options that allow you to import
routes from one routing table into another routing table based on certain criteria. In this scenario, you need to configure RIB groups on PE-1 and CE-1 to import
Internet routes from inet.0 into vpn-a.inet.0 and vice versa.
? Internet traffic from Site 2 takes the path of PE-2 -> PE-1 -> CE-1 -> PE-1 -> GW-1. This is because Site 2 does not have direct Internet access and needs to use
CE-1 as its default gateway for Internet traffic. Site 2 sends its Internet traffic to PE-2, which forwards it to PE-1 based on VPN-A routes. PE-1 then sends it to CE1 based on RIB group import policy. CE-1 then sends it back to PE-1 based on its default route pointing to GW-1. PE-1 then forwards it to GW-1 based on RIB
group import policy again.

Question 10

Which origin code is preferred by BGP?

Accepted Answer

BGP uses several attributes to select the best path for a destination prefix. One of these attributes is origin, which indicates how BGP learned about a route. The
origin attribute can have one of three values: IGP, EGP, or Incomplete. IGP means that the route was originated by a network or aggregate statement within BGP
or by redistribution from an IGP into BGP. EGP means that the route was learned from an external BGP peer (this value is obsolete since BGP version 4).
Incomplete means that the route was learned by some other means, such as redistribution from a static route into BGP. BGP prefers routes with lower origin
values, so Incomplete is preferred over EGP, which is preferred over IGP.