350-501 Networking Practice Test 9 — 15 Questions

Question 1

An SP is implementing IPv6 transition using MAP-T. Which encapsulation method does MAP-T use?

Accepted Answer

IPv4-IPv6 translation (NAT64-like). MAP-T (Mapping of Address and Port using Translation) uses IPv4-IPv6 translation (stateless NAT64-like) at the customer edge, not encapsulation.

Answer

MPLS label switching

Answer

IPv4 in IPv6 encapsulation

Answer

IPv6 in IPv4 encapsulation

Question 2

In IS-IS, which metric type supports traffic engineering (TE) and is required for segment routing?

Accepted Answer

Wide metrics (TLV 135/236/22). IS-IS wide metrics (TLV 135/236/22) support TE and segment routing; narrow metrics (TLV 128/130) are limited to 6-bit metrics.

Answer

Default metric (TLV 2)

Answer

Narrow metrics (TLV 128/130)

Answer

TE metric (TLV 138)

Question 3

Which BGP attribute influences inbound traffic to an AS by affecting the path selection of eBGP peers?

Accepted Answer

MED. MED (Multi-Exit Discriminator) is used to influence inbound traffic by suggesting to a neighbor AS which path to use.

Answer

LOCAL_PREF

Answer

Weight

Answer

AS_PATH

Question 4

An SP is deploying IS-IS fast convergence. Which mechanism triggers an immediate SPF computation when a neighbor fails?

Accepted Answer

BFD (Bidirectional Forwarding Detection). BFD (Bidirectional Forwarding Detection) provides sub-second failure detection and triggers SPF/PRC.

Answer

Partial Route Computation (PRC)

Answer

Event-driven SPF

Answer

IS-IS Hello multiplier

Question 5

In a BGP confederation, which AS number is used in the AS_PATH to prevent loops within the confederation?

Accepted Answer

Private AS numbers (64512-65535). Confederation uses private AS numbers (from 64512 to 65535) for sub-ASs, and these are prepended to the AS_PATH but not shown to external peers.

Answer

The same AS number as the confederation ID

Answer

Public AS numbers

Answer

No AS number is prepended

Question 6

An SP engineer is designing an OSPF network and wants to reduce the number of LSAs in a stub area. Which TWO area types would block Type 5 LSAs but allow Type 3 LSAs? (Choose two.)

Accepted Answer

NSSA. Stub and NSSA allow Type 3 LSAs but block Type 5 LSAs. Totally stubby blocks both Type 3 and Type 5.

Answer

Totally stubby area

Answer

Backbone area 0

Answer

Normal area

Question 7

An SP is deploying IPv6 using 6VPE. Which THREE components are required? (Choose three.)

Accepted Answer

Customer edge (CE) routers with IPv6 connectivity. 6VPE requires MPLS core, MP-BGP with VPNv6 address family, and CE routers running IPv6. LDP is used for label distribution in the core.

Answer

6rd tunneling

Answer

NAT64 translation

Question 8

An engineer is configuring IS-IS in a service provider network. The network uses wide metrics for traffic engineering. Which TLV is mandatory for IS-IS to carry traffic engineering (TE) information in accordance with RFC 5305?

Accepted Answer

TLV 22 (Extended IS Reachability). TLV 22 (Extended IS Reachability) is the mandatory TLV for IS-IS TE, defined in RFC 5305.

Answer

TLV 135 (Extended IP Reachability)

Answer

TLV 229 (Multi-Topology Reachable IPv4 Prefixes)

Answer

TLV 128 (IP Internal Reachability)

Question 9

In an IS-IS network, a router has a NET of 49.0001.1921.6800.1001.00. What does the '00' at the end represent?

Accepted Answer

SEL (NSAP Selector). The last byte '00' is the SEL (NSAP Selector), which is always '00' for IS-IS routing.

Answer

System ID

Answer

AFI

Answer

Area ID

Question 10

A service provider is deploying OSPFv3 for IPv6 in its core. The network uses multiple areas. Which LSA type is used by OSPFv3 to advertise prefix information for inter-area routes?

Accepted Answer

Inter-Area Prefix LSA (Type 0x2003). In OSPFv3, Inter-Area Prefix LSAs (Type 0x2003) are used to advertise prefixes from other areas.

Answer

Network LSA (Type 0x2002)

Answer

Intra-Area Prefix LSA (Type 0x2009)

Answer

Router LSA (Type 0x2001)

Question 11

An ISP is implementing BGP PIC (Prefix Independent Convergence) for edge routers. Which BGP feature must be enabled to support PIC for core-facing failures?

Accepted Answer

BGP additional-paths install. BGP PIC relies on installing a backup path in the FIB. For core-facing failures, BGP Fast External Fallover and BGP PIC with backup paths are used; specifically, 'bgp additional-paths install' is needed to install backup paths.

Answer

BGP deterministic-med

Answer

BGP route refresh

Answer

BGP bestpath as-path multipath-relax

Question 12

Which BGP attribute is used to prefer a specific entry point into an AS when multiple ASBRs are advertising the same prefix to a neighboring AS?

Accepted Answer

MED. MED (Multi-Exit Discriminator) is used to influence the inbound traffic by suggesting the preferred entry point.

Answer

LOCAL_PREF

Answer

WEIGHT

Answer

AS_PATH

Question 13

Which OSPF network type elects a Designated Router (DR) and Backup Designated Router (BDR) to reduce the number of adjacencies on a multi-access segment?

Accepted Answer

Broadcast. Broadcast network type uses DR/BDR election. Point-to-point and NBMA do not elect DR/BDR (NBMA does elect DR/BDR but is less common).

Answer

Point-to-point

Answer

Loopback

Answer

Point-to-multipoint

Question 14

An SP is designing an OSPF network with a totally stubby area to reduce the LSA database. Which LSA types are blocked by default in a totally stubby area?

Accepted Answer

Type 3, Type 4, and Type 5. Totally stubby area blocks Type 4 (ASBR Summary) and Type 5 (External) LSAs, and also Type 3 (Summary) LSAs except for the default route.

Answer

Type 3 and Type 5 only

Answer

Type 5 only

Answer

Type 4 and Type 5 only

Question 15

In IS-IS, what is the result of configuring wide metrics on all interfaces?

Accepted Answer

Higher metric values are supported for traffic engineering. Wide metrics (24-bit or 32-bit) allow values up to 16,777,215 or higher, enabling TE and faster convergence with precise metric adjustments.

Answer

Only L2 routers can use wide metrics

Answer

Metrics are limited to 63

Answer

IS-IS TLVs are backward compatible with narrow metrics