ECP-206 Exam Dumps - Ericsson Certified Associate - IP Networking

Two statements that are correct for LDP are:

• LSRs send UDP hello messages for neighbor discovery. LDP is a protocol that distributes labels for MPLS forwarding along the shortest path calculated by an IGP. LDP uses two types of messages: discovery messages and session messages. Discovery messages are used to discover and maintain adjacency with other LSRs that support LDP. Discovery messages are sent as UDP datagrams to the well-known multicast address 224.0.0.2 (all routers on this subnet) on port 64634.
• LSRs use TCP to negotiate LDP session parameters. Session messages are used to establish, maintain, and terminate LDP sessions between LSRs. Session messages are also used to exchange label mappings, notification messages, and keepalive messages. Session messages are sent as TCP segments to port 64634.

References: Ldp | Microsoft Learn, Label Distribution Protocol - Wikipedia

The protocol that would be used to bundle multiple Ethernet ports into a virtual link with an aggregated bandwidth is LACP, which stands for Link Aggregation Control Protocol. LACP is a protocol that allows two or more devices to negotiate the formation of a link aggregation group (LAG), also known as an EtherChannel or a port channel. A LAG combines multiple physical links into one logical link that provides increased bandwidth, load balancing, and redundancy. LACP is defined in IEEE 802.3ad and 802.1AX standards12.

References: Link Aggregation Control Protocol - Wikipedia, What is “link aggregation” and how does it benefit your network? | PC Gamer

The code that is commonly used to assign higher priority to VoIP traffic is EF, which stands for Expedited Forwarding. EF is a per-hop behavior (PHB) defined by the Differentiated Services (DiffServ) model for QoS. EF provides low delay, low jitter, and low loss for real-time applications such as VoIP. EF is marked by setting the DSCP value to 101110, which corresponds to decimal 4678. AF31, which stands for Assured Forwarding class 3 low drop probability, is another PHB defined by DiffServ, but it provides lower priority than EF. AF31 is marked by setting the DSCP value to 011010, which corresponds to decimal 2678. DF, which stands for Default Forwarding, is a PHB defined by DiffServ that provides best-effort service for unmarked traffic. DF is marked by setting the DSCP value to 000000, which corresponds to decimal 078. AF11, which stands for Assured Forwarding class 1 low drop probability, is another PHB defined by DiffServ, but it provides lower priority than EF and AF31. AF11 is marked by setting the DSCP value to 001010, which corresponds to decimal 1078.

References: Differentiated services - Wikipedia, Solved: Cisco VoIP Phone traffic marking - Cisco Community

OSPF runs directly on IP, while IS-IS runs directly on Ethernet. This means that OSPF uses IP addresses to identify routers and links, while IS-IS uses MAC addresses or other link-layer identifiers. OSPF also requires an IP header for each packet, while IS-IS does not. Both OSPF and IS-IS are link state protocols, which means that they flood information about the network topology to all routers in the same area or domain. References: Ericsson IP Networking - Routing Protocols, Ericsson Router 6000 Series - Ericsson

The conceptual table created by routing protocols that is used when processing an IP packet is the forwarding information base (FIB). The FIB is a table that contains the bestroutes to reach each destination network prefix, along with the outgoing interface and the next-hop address for each route. The FIB is derived from the routing information base (RIB), which is a table that contains all the routes learned from different routing protocols and sources. The FIB is used by the router to make fast forwarding decisions for each incoming packet, based on its destination address12.

References: Security Hardening Checklist Guide for Cisco Routers/Switches in 10 Steps, VLAN - Wikipedia

The Area ID to which the router belongs is 49.00F0.0100. The Area ID is a variable-length field in the NSAP address that identifies the area to which the router belongs. The Area ID can be between 1 and 13 bytes long, but it must start and end with an octet (8 bits). The NSAP address is composed of three parts: the authority and format identifier (AFI), the area ID, and the system ID. The AFI is a one-octet field that indicates the format and authority of the rest of the address. The system ID is a fixed-length field of six octets that uniquely identifies the router within an area. The NSAP address also has a network selector (NSEL) field, which is a one-octet field that identifies the network layer service to which a packet should be sent. For IS-IS routers, the NSEL must always be 00.

In this question, the NSAP address is 49.00F0.0100.5012.3010.00. This means that:

• The AFI is 49, which indicates a private address.
• The Area ID is 00F0.0100, which is four octets long and starts and ends with an octet.
• The system ID is 5012.3010, which is six octets long and identifies the router within the area.
• The NSEL is 00, which indicates IS-IS.

Therefore, the answer is B.

References: Ericsson IP Networking - Routing Protocols, IS-IS NSAP address - Cisco Community, Understanding IS-IS NSAP Addresses - Todd Lammle, LLC, IS-IS - Nokia, Network service access point address - Wikipedia

IPsec provides two main features: protecting packets from modification and hiding the content of packets from observation. IPsec protects packets from modification by using cryptographic algorithms to generate and verify message authentication codes (MACs) or digital signatures for each packet. These mechanisms ensure that the packets have not been tampered with or altered in transit by unauthorized parties. IPsec hides the content of packets from observation by using encryption algorithms to scramble the payload of each packet. This prevents eavesdroppers or interceptors from reading or analyzing the data carried by the packets12.

References: What is IPsec? | How IPsec VPNs work | Cloudflare, IPsec - Wikipedia

To differentiate traffic types for the purpose of prioritization in their Ethernet LAN and IP/MPLS backbone, an operator can use the following three fields:

• Traffic Class (TC): This is a 3-bit field in the MPLS label that can be used to indicate the priority or class of service (CoS) of the packet. The TC field can be mapped to the DSCP field in the IP header or the PCP field in the Ethernet header. The TC field can be used by MPLS routers to apply different per-hop behaviors (PHBs) such as queuing, scheduling, and dropping policies to different traffic classes12.
• DSCP: This is a 6-bit field in the IP header that can be used to mark packets according to the differentiated services (DiffServ) model. The DSCP field can indicate the per-hop behavior (PHB) that the packet should receive at each router along its path. The DSCP field can be mapped to the TC field in the MPLS label or the PCP field in the Ethernet header. The DSCP field can be used by IP routers to provide QoS for different traffic types34.
• PCP: This is a 3-bit field in the Ethernet header that can be used to mark packets according to the IEEE 802.1Q standard. The PCP field can indicate the priority or class of service (CoS) of the packet on an Ethernet LAN. The PCP field can be mapped to the TC field in the MPLS label or the DSCP field in the IP header. The PCP field can be used by Ethernet switches to provide QoS for different traffic types56.

References: MPLS Traffic Engineering - DiffServ-Aware Traffic Engineering, MPLS Traffic Engineering - DiffServ-Aware Traffic Engineering Configuration Guide, Differentiated services - Wikipedia, DSCP and Precedence Values - Cisco, 802.1Q VLAN IDs and Ethernet Interface Types - Juniper Networks, Introduction to Virtual LANs (VLANs) and Tagging - Ubiquiti Support and Help Center