Please keep at least one language enabled. || కనీసం ఒక భాషను ఎంచుకోండి.
Question 1
ప్రశ్న 1
What is packet filtering in the context of a firewall?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Packet filtering controls network traffic by comparing packet information with a configured ruleset.
• Basic filters commonly use header information such as source and destination addresses, protocol and ports where applicable.
• Packet filtering is an access-control function and is different from encryption or address translation.
• Basic filters commonly use header information such as source and destination addresses, protocol and ports where applicable.
• Packet filtering is an access-control function and is different from encryption or address translation.
వివరణ:
Question 2
ప్రశ్న 2
Which combination contains information commonly used by an IP packet-filtering firewall to make filtering decisions?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Packet filters commonly examine source and destination IP addresses.
• They can also examine the IP protocol and, for protocols such as TCP and UDP, source or destination port numbers.
• These values are contained in network or transport-layer headers and are relevant to traffic-control decisions.
• They can also examine the IP protocol and, for protocols such as TCP and UDP, source or destination port numbers.
• These values are contained in network or transport-layer headers and are relevant to traffic-control decisions.
వివరణ:
Question 3
ప్రశ్న 3
Which statement correctly describes a basic stateless packet filter?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A stateless packet filter evaluates packets without maintaining a connection-state table for each traffic flow.
• Its decision is based principally on information available in the packet and the configured ruleset.
• Stateful inspection differs because it tracks the state of network connections.
• Its decision is based principally on information available in the packet and the configured ruleset.
• Stateful inspection differs because it tracks the state of network connections.
వివరణ:
Question 4
ప్రశ్న 4
What are the two fundamental actions normally associated with a packet-filtering access-control rule?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Packet-filtering rules determine whether matching traffic should be permitted or denied.
• A packet matching an allow rule can continue according to the device's processing policy, while traffic matching a deny rule is blocked.
• Compression, encryption and software installation are separate functions.
• A packet matching an allow rule can continue according to the device's processing policy, while traffic matching a deny rule is blocked.
• Compression, encryption and software installation are separate functions.
వివరణ:
Question 5
ప్రశ్న 5
A firewall administrator wants to block packets specifically when they are addressed to the protected server 10.10.5.20, regardless of which external host sent them. Which packet field is most directly relevant to identifying that server?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The destination IP address identifies the IP host that a packet is intended to reach.
• To match traffic specifically addressed to 10.10.5.20, the destination-address field is therefore directly relevant.
• The source IP identifies where the packet originated rather than the intended destination.
• To match traffic specifically addressed to 10.10.5.20, the destination-address field is therefore directly relevant.
• The source IP identifies where the packet originated rather than the intended destination.
వివరణ:
Question 6
ప్రశ్న 6
Which packet-header field enables a filter to distinguish, at the IP protocol level, between traffic such as TCP, UDP and ICMP?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The IP header contains a protocol indicator identifying the encapsulated upper-layer protocol.
• Packet-filtering rules can therefore distinguish traffic such as TCP, UDP and ICMP.
• Port numbers provide further filtering information for transport protocols such as TCP and UDP.
• Packet-filtering rules can therefore distinguish traffic such as TCP, UDP and ICMP.
• Port numbers provide further filtering information for transport protocols such as TCP and UDP.
వివరణ:
Question 7
ప్రశ్న 7
A packet-filtering rule must distinguish ordinary TCP web traffic destined for port 80 from TCP traffic destined for port 22. Which information is most directly required in addition to the IP addresses?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• TCP destination port numbers identify the destination service endpoint for TCP communication.
• A filter can therefore distinguish TCP traffic destined for port 80 from traffic destined for port 22.
• IP addresses identify hosts or interfaces but do not by themselves distinguish these two destination ports.
• A filter can therefore distinguish TCP traffic destined for port 80 from traffic destined for port 22.
• IP addresses identify hosts or interfaces but do not by themselves distinguish these two destination ports.
వివరణ:
Question 8
ప్రశ్న 8
When a packet-filtering rule is applied inbound on a router or firewall interface, when is the packet evaluated with respect to that interface?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Inbound filtering applies to traffic arriving on the interface.
• The device evaluates the packet against the applicable inbound rules before forwarding permitted traffic onward.
• Outbound filtering is instead associated with traffic leaving through an interface.
• The device evaluates the packet against the applicable inbound rules before forwarding permitted traffic onward.
• Outbound filtering is instead associated with traffic leaving through an interface.
వివరణ:
Question 9
ప్రశ్న 9
A public web server has IP address 203.0.113.10 and must accept inbound HTTPS traffic. Which packet-filter rule most directly permits only the required protocol, destination and service described in the question?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• HTTPS normally uses TCP destination port 443.
• The server is the destination of the inbound connection, so the rule must identify 203.0.113.10 as the destination address.
• Therefore TCP traffic destined specifically for 203.0.113.10:443 matches the stated requirement.
• The server is the destination of the inbound connection, so the rule must identify 203.0.113.10 as the destination address.
• Therefore TCP traffic destined specifically for 203.0.113.10:443 matches the stated requirement.
వివరణ:
Question 10
ప్రశ్న 10
Which statement best distinguishes stateful inspection from basic stateless packet filtering?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Stateful inspection maintains information about active connections in a state table.
• It can evaluate a packet in the context of the expected state of an existing connection.
• A basic stateless packet filter instead evaluates packets individually without maintaining equivalent per-connection state.
• It can evaluate a packet in the context of the expected state of an existing connection.
• A basic stateless packet filter instead evaluates packets individually without maintaining equivalent per-connection state.
వివరణ:
Question 11
ప్రశ్న 11
A basic stateless packet filter permits an internal client to initiate an outbound TCP connection. Which statement correctly identifies a limitation when the return packets arrive?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A stateless packet filter does not maintain a connection-state table linking packets into established sessions.
• Return traffic must therefore satisfy the applicable packet-filtering rules rather than being recognized through maintained connection state.
• Stateful inspection was developed in part to provide this additional connection awareness.
• Return traffic must therefore satisfy the applicable packet-filtering rules rather than being recognized through maintained connection state.
• Stateful inspection was developed in part to provide this additional connection awareness.
వివరణ:
Question 12
ప్రశ్న 12
Under a default-deny packet-filtering policy, what should happen to a packet that does not match any rule explicitly permitting it?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• A default-deny security approach permits only traffic that is explicitly authorized.
• Traffic for which no permitted exception exists is blocked.
• This reduces exposure compared with a policy that allows unspecified traffic by default.
• Traffic for which no permitted exception exists is blocked.
• This reduces exposure compared with a policy that allows unspecified traffic by default.
వివరణ:
Question 13
ప్రశ్న 13
Which statement about the networking information examined by a basic IP packet filter is technically correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Basic packet filtering primarily provides network-level access control using packet-header information.
• IP source and destination addresses are important filtering fields, while TCP or UDP ports can provide transport-layer service information.
• Understanding complete application commands is associated with more application-aware firewall technologies rather than being required for basic packet filtering.
• IP source and destination addresses are important filtering fields, while TCP or UDP ports can provide transport-layer service information.
• Understanding complete application commands is associated with more application-aware firewall technologies rather than being required for basic packet filtering.
వివరణ:
Question 14
ప్రశ్న 14
Which capability is generally associated more strongly with an application-proxy gateway than with a basic stateless packet filter?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Application-proxy gateways operate with application-level awareness and can inspect actual application traffic content.
• They can make access-control decisions using information from application protocol headers or payloads.
• A basic stateless packet filter is principally concerned with packet-header fields rather than complete application content.
• They can make access-control decisions using information from application protocol headers or payloads.
• A basic stateless packet filter is principally concerned with packet-header fields rather than complete application content.
వివరణ:
Question 15
ప్రశ్న 15
A security administrator wants to block all IP packets originating from host 198.51.100.27, irrespective of their destination. Which filtering criterion is most directly required?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The source IP address identifies the IP host from which the packet originated.
• Matching source IP 198.51.100.27 therefore targets packets originating from that host.
• Matching the destination address would instead target packets being sent to that host.
• Matching source IP 198.51.100.27 therefore targets packets originating from that host.
• Matching the destination address would instead target packets being sent to that host.
వివరణ:
Question 16
ప్రశ్న 16
Internal clients must be permitted to send UDP DNS queries specifically to the resolver 192.0.2.53 on destination port 53. Which rule most accurately represents that requirement?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• The scenario explicitly specifies UDP DNS queries to one resolver on destination port 53.
• A precise packet-filter rule can therefore match the authorized internal source range, UDP protocol, destination IP 192.0.2.53 and destination port 53.
• A broader rule allowing all UDP traffic would permit more communication than the stated requirement.
• A precise packet-filter rule can therefore match the authorized internal source range, UDP protocol, destination IP 192.0.2.53 and destination port 53.
• A broader rule allowing all UDP traffic would permit more communication than the stated requirement.
వివరణ:
Question 17
ప్రశ్న 17
Consider the following statements about basic packet filters:
1. They can use source and destination IP addresses as filtering criteria.
2. They can use protocol and TCP/UDP port information where applicable.
3. A basic stateless packet filter maintains a connection-state table for every permitted flow.
4. Filtering rules can specify whether matching traffic is permitted or denied.
Which statements are correct?
1. They can use source and destination IP addresses as filtering criteria.
2. They can use protocol and TCP/UDP port information where applicable.
3. A basic stateless packet filter maintains a connection-state table for every permitted flow.
4. Filtering rules can specify whether matching traffic is permitted or denied.
Which statements are correct?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Statements 1 and 2 correctly identify common packet-filtering criteria.
• Statement 3 is false because maintaining connection state distinguishes stateful inspection from basic stateless filtering.
• Statement 4 is correct because packet-filter rules commonly express permit or deny decisions.
• Statement 3 is false because maintaining connection state distinguishes stateful inspection from basic stateless filtering.
• Statement 4 is correct because packet-filter rules commonly express permit or deny decisions.
వివరణ:
Question 18
ప్రశ్న 18
Assertion (A): A basic stateless packet filter cannot determine that an incoming packet belongs to an already permitted connection by looking up that connection in a maintained state table.
Reason (R): Stateless packet filtering does not maintain per-connection state information in such a table.
Choose the correct answer.
Reason (R): Stateless packet filtering does not maintain per-connection state information in such a table.
Choose the correct answer.
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Stateless packet filters evaluate packets without maintaining an equivalent table of active connection states.
• They therefore cannot use such a state table to establish that an incoming packet belongs to a previously permitted connection.
• Both statements are true, and the Reason directly explains the Assertion.
• They therefore cannot use such a state table to establish that an incoming packet belongs to a previously permitted connection.
• Both statements are true, and the Reason directly explains the Assertion.
వివరణ:
Question 19
ప్రశ్న 19
Match List I with List II:
List I
(a) Source IP address
(b) Destination IP address
(c) Protocol field
(d) Destination port
List II
1. Identifies the intended IP destination host or interface
2. Can distinguish an IP payload type such as TCP, UDP or ICMP
3. Identifies the IP source from which a packet originated
4. Can identify the intended TCP/UDP service endpoint
Choose the correct matching code.
List I
(a) Source IP address
(b) Destination IP address
(c) Protocol field
(d) Destination port
List II
1. Identifies the intended IP destination host or interface
2. Can distinguish an IP payload type such as TCP, UDP or ICMP
3. Identifies the IP source from which a packet originated
4. Can identify the intended TCP/UDP service endpoint
Choose the correct matching code.
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Source IP identifies where the IP packet originated, giving (a)-3.
• Destination IP identifies the intended IP destination, giving (b)-1, while the Protocol field identifies the encapsulated protocol, giving (c)-2.
• For TCP or UDP traffic, the destination port can identify the intended service endpoint, giving (d)-4.
• Destination IP identifies the intended IP destination, giving (b)-1, while the Protocol field identifies the encapsulated protocol, giving (c)-2.
• For TCP or UDP traffic, the destination port can identify the intended service endpoint, giving (d)-4.
వివరణ:
Question 20
ప్రశ్న 20
A firewall must block inbound Telnet connections to a server while allowing inbound HTTPS connections to the same server. Assuming standard service ports, which packet information allows a TCP packet filter to distinguish these two services most directly?
Select an option first. || ముందుగా ఒక సమాధానాన్ని ఎంచుకోండి.
Explanation:
• Telnet and HTTPS can both use TCP but normally use different destination service ports.
• Telnet conventionally uses TCP port 23, while HTTPS conventionally uses TCP port 443.
• A TCP packet-filtering rule can therefore distinguish these services using the destination port number.
• Telnet conventionally uses TCP port 23, while HTTPS conventionally uses TCP port 443.
• A TCP packet-filtering rule can therefore distinguish these services using the destination port number.
వివరణ:
Answer Key సమాధానాల పట్టిక
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Question 1 ప్రశ్న 1Answer: C. A method that permits or blocks network packets according to rules based mainly on packet-header information సమాధానం: C.
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Question 2 ప్రశ్న 2Answer: A. Source IP address, destination IP address, protocol and TCP/UDP port numbers where applicable సమాధానం: A.
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Question 3 ప్రశ్న 3Answer: D. It evaluates packets against filtering rules without maintaining the state of each network connection. సమాధానం: D.
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Question 4 ప్రశ్న 4Answer: B. Permit and deny సమాధానం: B.
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Question 5 ప్రశ్న 5Answer: B. Destination IP address సమాధానం: B.
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Question 6 ప్రశ్న 6Answer: D. IP protocol field సమాధానం: D.
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Question 7 ప్రశ్న 7Answer: A. TCP destination port సమాధానం: A.
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Question 8 ప్రశ్న 8Answer: C. As the packet arrives on that interface before being forwarded onward సమాధానం: C.
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Question 9 ప్రశ్న 9Answer: D. Permit TCP traffic to destination 203.0.113.10 on destination port 443. సమాధానం: D.
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Question 10 ప్రశ్న 10Answer: B. Stateful inspection tracks connection state, while a basic stateless packet filter evaluates packets without maintaining equivalent connection-state information. సమాధానం: B.
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Question 11 ప్రశ్న 11Answer: C. The filter cannot identify the return packets as belonging to the earlier connection by consulting a maintained connection-state table, because it does not keep such state. సమాధానం: C.
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Question 12 ప్రశ్న 12Answer: A. It should be denied. సమాధానం: A.
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Question 13 ప్రశ్న 13Answer: A. It can use network-layer source and destination IP information and can also use transport-layer port information for protocols such as TCP and UDP. సమాధానం: A.
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Question 14 ప్రశ్న 14Answer: C. Understanding an application protocol and inspecting application-level traffic content సమాధానం: C.
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Question 15 ప్రశ్న 15Answer: B. Source IP address = 198.51.100.27 సమాధానం: B.
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Question 16 ప్రశ్న 16Answer: D. Permit UDP traffic from the authorized internal source range to destination 192.0.2.53 on destination port 53. సమాధానం: D.
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Question 17 ప్రశ్న 17Answer: C. 1, 2 and 4 only సమాధానం: C.
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Question 18 ప్రశ్న 18Answer: D. Both Assertion and Reason are true, and Reason is the correct explanation of Assertion. సమాధానం: D.
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Question 19 ప్రశ్న 19Answer: A. (a)-3, (b)-1, (c)-2, (d)-4 సమాధానం: A.
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Question 20 ప్రశ్న 20Answer: B. The TCP destination port number సమాధానం: B.