Ericsson Certified Associate - IP Networking ECP-206 Exam Questions

Answer : B

The router function that advertises external routes in OSPF is ASBR, which stands for Autonomous System Boundary Router. An ASBR is a router that connects an OSPF domain to another routing domain, such as another OSPF domain or a different routing protocol domain. An ASBR can redistribute routes from other routing domains into OSPF as external routes, which are carried in type 5 or type 7 LSAs. External routes have two types: E1 and E2.E1 routes include the cost from the ASBR to the destination, while E2 routes only include the cost advertised by the ASBR34.

Answer : A, B, C

IPv6 link-local addresses are designed to be used in three situations: for neighbor discovery, for local IP communication on the IPv6 capable routers, and for addressing on a single link for purposes such as auto-address configuration. Neighbor discovery is a protocol that allows IPv6 nodes to discover each other and learn their link-layer addresses on a local network.Neighbor discovery uses link-local addresses to send and receive messages such as router advertisements, router solicitations, neighbor advertisements, and neighbor solicitations34. Local IP communication on the IPv6 capable routers refers to the ability of routers to exchange routing information or management traffic using their link-local addresses as source and destination addresses.This reduces the need for global unicast addresses on router interfaces that are not reachable from outside the local network35. Addressing on a single link for purposes such as auto-address configuration refers to the use of link-local addresses to enable IPv6 nodes to obtain an address without manual configuration or a DHCP server. Link-local addresses can be automatically derived from the interface identifier in the modified EUI-64 format or randomly generated.Link-local addresses can also be used to test the connectivity of a link before obtaining a global unicast address36.

Answer : A, C, E

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.

Answer : D

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 best routes 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.

Answer : B

According to RFC1918, there are three network blocks reserved as private networks that are not allocated to any specific organization and are not routable on the public Internet. These are:

10.0.0.0/8 (10.0.0.0 - 10.255.255.255)

172.16.0.0/12 (172.16.0.0 - 172.31.255.255)

192.168.0.0/16 (192.168.0.0 - 192.168.255.255)

Out of these, only option B (10.254.1.0/24) falls within one of the private network blocks (10.0.0.0/8). Option A (172.16.1.0/9) is not valid because it exceeds the /12 prefix length of the private network block (172.16.0.0/12). Option C (193.168.1.0/24) is not valid because it does not belong to any of the private network blocks, and is actually assigned to RIPE NCC as a public network block . Option D (172.15.1.0/24) is also not valid because it does not belong to any of the private network blocks, and is actually assigned to ARIN as a public network block .Reference:RFC 1918: Address Allocation for Private Internets,Private network - Wikipedia, [RIPE NCC IPv4 Address Space Chart], [ARIN WHOIS Database Search]

Answer : A, D

Two statements that are true about the Ericsson Router 6000 series are:

The Router 6000 uses the same building practice and accessories as the Ericsson Radio System. The Ericsson Radio System is a modular and scalable radio access network solution that supports multiple standards, bands, and layers. The Router 6000 series is fully integrated into the Ericsson Radio System, using the same building practice and accessories such as mounting kits, cables, power supplies, etc.This simplifies installation, operation, and maintenance of both radio and transport equipment78.

The Router 6000 products range from all-outdoor small site routers to large aggregation routers. The Router 6000 series consists of three main products: the Router 6672 for access, the Router 6675 for pre-aggregation, and the Router 6274 for metro aggregation. The Router 6672 is an all-outdoor small cell site router with high-capacity and low-power consumption. The Router 6675 is a combined access and E-RAN switch with hardware-accelerated IPSec and high-accuracy internal clock.The Router 6274 is a high-capacity metro aggregation router with SDN functionality and flexible interface options78.

Answer : A

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.