ATT ADVANCED TECHNICAL
ASSESSMENT - LEVEL 3 QUESTIONS
AND ANSWERS 2026
1. In BGP (Border Gateway Protocol), which attribute is used to prevent routing loops within
an Autonomous System (AS) when Route Reflectors are implemented?
A. AS_PATH
B. CLUSTER_LIST
C. NEXT_HOP
D. MED (Multi-Exit Discriminator)
Answer: B
Conceptual Explanation: The CLUSTER_LIST attribute is a non-transitive BGP attribute
that contains the list of Cluster IDs that a route has passed through to prevent loops in
Route Reflector environments.
2. According to the Shannon-Hartley theorem, what happens to the channel capacity if the
signal-to-noise ratio (SNR) is increased while the bandwidth remains constant?
A. The capacity decreases.
B. The capacity increases linearly.
,C. The capacity remains unchanged.
D. The capacity increases logarithmically.
Answer: D
Conceptual Explanation: The formula C = B log2(1 + S/N) shows that capacity increases
logarithmically as the SNR (S/N) improves.
3. Which field in the MPLS (Multiprotocol Label Switching) header is specifically used to
prevent packets from looping indefinitely in the network?
A. Label Value
B. Traffic Class (Exp)
C. Bottom of Stack (S)
D. Time to Live (TTL)
Answer: D
Conceptual Explanation: The 8-bit TTL field in the MPLS header performs the same
function as the TTL in the IP header, decrementing at each hop to prevent infinite loops.
4. In an IPv6 address, how many bits are typically allocated for the interface identifier when
using SLAAC (Stateless Address Autoconfiguration)?
A. 32 bits
B. 64 bits
C. 48 bits
, D. 128 bits
Answer: B
Conceptual Explanation: SLAAC typically uses a /64 prefix for the network portion and 64
bits for the interface identifier, often derived from the MAC address using EUI-64.
5. What is the primary difference between RAID 5 and RAID 6 configurations in terms of data
protection?
A. RAID 6 uses mirroring, while RAID 5 uses parity.
B. RAID 5 requires a minimum of five drives, while RAID 6 requires six.
C. RAID 6 can survive the failure of two simultaneous disk drives, whereas RAID 5 can only
survive one.
D. RAID 6 is faster for write operations than RAID 5.
Answer: C
Conceptual Explanation: RAID 6 uses dual parity, allowing the array to remain functional
even if two disks fail simultaneously, compared to RAID 5’s single parity.
6. Which OSI layer is responsible for segmenting data and ensuring end-to-end
communication with error recovery and flow control?
A. Network Layer
B. Data Link Layer
C. Transport Layer
ASSESSMENT - LEVEL 3 QUESTIONS
AND ANSWERS 2026
1. In BGP (Border Gateway Protocol), which attribute is used to prevent routing loops within
an Autonomous System (AS) when Route Reflectors are implemented?
A. AS_PATH
B. CLUSTER_LIST
C. NEXT_HOP
D. MED (Multi-Exit Discriminator)
Answer: B
Conceptual Explanation: The CLUSTER_LIST attribute is a non-transitive BGP attribute
that contains the list of Cluster IDs that a route has passed through to prevent loops in
Route Reflector environments.
2. According to the Shannon-Hartley theorem, what happens to the channel capacity if the
signal-to-noise ratio (SNR) is increased while the bandwidth remains constant?
A. The capacity decreases.
B. The capacity increases linearly.
,C. The capacity remains unchanged.
D. The capacity increases logarithmically.
Answer: D
Conceptual Explanation: The formula C = B log2(1 + S/N) shows that capacity increases
logarithmically as the SNR (S/N) improves.
3. Which field in the MPLS (Multiprotocol Label Switching) header is specifically used to
prevent packets from looping indefinitely in the network?
A. Label Value
B. Traffic Class (Exp)
C. Bottom of Stack (S)
D. Time to Live (TTL)
Answer: D
Conceptual Explanation: The 8-bit TTL field in the MPLS header performs the same
function as the TTL in the IP header, decrementing at each hop to prevent infinite loops.
4. In an IPv6 address, how many bits are typically allocated for the interface identifier when
using SLAAC (Stateless Address Autoconfiguration)?
A. 32 bits
B. 64 bits
C. 48 bits
, D. 128 bits
Answer: B
Conceptual Explanation: SLAAC typically uses a /64 prefix for the network portion and 64
bits for the interface identifier, often derived from the MAC address using EUI-64.
5. What is the primary difference between RAID 5 and RAID 6 configurations in terms of data
protection?
A. RAID 6 uses mirroring, while RAID 5 uses parity.
B. RAID 5 requires a minimum of five drives, while RAID 6 requires six.
C. RAID 6 can survive the failure of two simultaneous disk drives, whereas RAID 5 can only
survive one.
D. RAID 6 is faster for write operations than RAID 5.
Answer: C
Conceptual Explanation: RAID 6 uses dual parity, allowing the array to remain functional
even if two disks fail simultaneously, compared to RAID 5’s single parity.
6. Which OSI layer is responsible for segmenting data and ensuring end-to-end
communication with error recovery and flow control?
A. Network Layer
B. Data Link Layer
C. Transport Layer
