〇：The use of IM can be stopped by simply blocking certain ports on the network firewall.

Instant messaging (IM) allows people to communicate with each other via real-time and personal chat room types. These technologies will have the ability to transfer files. Users install an IM client and are assigned a unique identifier; they provide this unique identifier to anyone they wish to communicate with via IM. ineffective.

Another way to answer the question is to say that the question itself confirms our understanding of security, and then we can lay down the assumption that “should not be included in the presentation” means that we should not say anything that will later be held liable. There will be far more events that indicate that there is a possibility than events that say there is no possibility at all.

×：Sensitive data and files can be transferred from system to system via IM.

This is incorrect because in addition to text messages, instant messaging allows files to be transferred from system to system. These files could contain sensitive information, putting the company at business or legal risk. And sharing files via IM will use that much network bandwidth and impact network performance.

×：Users can be subjected to attacks posing as legitimate senders from malware containing information.

Incorrect because it is true. Due to lack of strong authentication, accounts can be falsified because there is to accept information from malicious users of the legitimate sender, not the receiver. There will also be numerous buffer overflows and malformed packet attacks that have been successful with different IM clients.

×：A security policy is needed specifying IM usage limits.

This is incorrect because his presentation should include the need for a security policy specifying IM usage restrictions. This is only one of several best practices to protect the environment from IM-related security breaches. Other best practices include upgrading IM software to a more secure version that configures the firewall to block IM traffic, implementing a corporate IM server so that only internal employees communicate within the organization’s network, and implementing an integrated Includes implementing an antivirus/firewall product.

Each IPSec VPN device will have at least one security association (SA) for each secure connection it uses; the SA, which is critical to the IPSec architecture, is the device’s need to support IPSec connections over VPN connections This is a record of the configuration that needs to be in place.

UDP (User Datagram Protocol) floods are often used in distributed denial of service (DDOS) attacks because they are connectionless and yet allow for easy generation of UDP messages from various scripting and compilation languages. UDP is a datagram protocol.

〇：IGRP

The Internal Gateway Routing Protocol (IGRP) is a distance vector routing protocol developed by and proprietary to Cisco Systems, Inc. Whereas the Routing Information Protocol (RIP) uses one criterion to find the optimal path between source and destination, IGRP uses five criteria to make an “optimal route” determination. The network administrator can set weights on these different metrics so that the protocol works optimally in its particular environment.

×：RIP  

Routing Information Protocol (RIP) is incorrect because it is not proprietary; RIP allows routers to exchange routing table data and calculate the shortest distance between source and destination. It is considered a legacy protocol due to poor performance and lack of features. It should be used in smaller networks.

×：BGP

Border Gateway Protocol (BGP) is incorrect because it is an Exterior Gateway Protocol (EGP); BGP allows routers in different ASes to share routing information to ensure effective and efficient routing between different networks. BGP is used by Internet Service Providers.

×：OSPF  

OSPF is incorrect because it is not proprietary; it uses a link-state algorithm to transmit information in the OSPF routing table. Smaller and more frequent routing table updates.

Matrix is not a network topology. Ring, mesh, and star are network topologies.

〇：Make the mail relay server available to everyone.

This is a question of choosing the “ineffective” one. An open mail relay server is not an effective countermeasure against spam. In fact, spammers often use spammers to distribute spam, because the attackers can hide their identities. An open mail relay server is an SMTP server configured to allow inbound SMTP connections from anyone on the Internet, and many relays are properly configured to prevent attackers from distributing spam and pornography. Thus, the correct answer is “have an email relay server available to everyone.” will be.

×：Build a properly configured mail relay server.

A properly configured mail relay server can also suppress spam mail.

×：Perform filtering at the e-mail gateway.

Filtering emails that are considered spam mail at the gateway will help to prevent spam mail.

×：Filtering at the client.

Filtering spam mail at the client, i.e., in a mailing application such as Outlook, is considered to be a countermeasure against spam mail.

War Dialing is the indiscriminate and repeated act of cracking dial-ups in search of dial-up lines, such as those for non-public internal networks. It automatically scans a list of telephone numbers, usually dialing all numbers in the local area code, and searches modems, computers, bulletin board systems, and fax machines.

〇：For early detection or enclosure in the event of an attack.

Attackers will conduct an investigation before launching a substantial attack. In such cases, a vulnerable network can provide preventative information such as where the attacker is accessing the network from. This is because only an attacker would have the incentive to break into the network. Vulnerable network domains, such as honeypots, make this kind of intrusion easier and clarify the attacker’s behavior. Thus, the correct answer is “to detect or enclose them early in the event of an attack.” will be

×：Debugging environment for when a system outage occurs in the current environment.

The answer is not to intentionally create a vulnerable environment. It is only the result of creating an environment that is vulnerable.

×：Aiming to prevent regressions due to old vulnerabilities.

Even if it is an old vulnerability, it should be addressed and there is no point in allowing it to remain.

×：A special environment for running a product with a low version that is no longer supported.

It is not an answer to intentionally create a vulnerable environment. It is merely the result of creating an environment that is vulnerable.

〇：IP Session Restriction via Media Gateway

The VoIP Media Gateway translates Internet Protocol (VoIP) voice over time division multiplexing (TDM) voice to and from. As a security measure, the number of calls through the Media Gateway should be limited. The Media Gateway is vulnerable to denial-of-service attacks, hijacking, and other types of attacks.

×：Identification of Rogue Devices  

Incorrect, as rogue devices on both IP telephony and data networks need to be identified.

×：Implementation of Authentication

Incorrect because authentication is recommended for both data and voice networks.

×：Encryption of packets containing sensitive information

Incorrect because sensitive data can be transmitted over either voice or data networks and must be encrypted in both cases. Eavesdropping is a very real threat for VoIP networks.

〇：How routers are centrally managed and control packets based on the controller’s instructions 

Software-defined networks (SDN) are intended to facilitate centralized management of routing decisions and to separate the router’s logical functions of passing data between the routing decision and the interface and making its mechanical functions.SDN architecture is a scalable, a programmable, and is intended to be a standard method of providing router control logic. Therefore, the correct answer is “a way for routers to be centrally managed and control packets based on the controller’s instructions.

×：Mapping between MAC and IP addresses.

ARP table.

×：Updating the routing table in a dynamic way.

Explanation of dynamic routing.

×：A method in which routers communicate with each other to update the routing table when an event occurs.

This is an explanation of routing control in case of communication failure.

〇：Socket

UDP (User Datagram Protocol) and TCP (Transmission Control Protocol) are transport protocols used by applications to retrieve data over a network. Both use ports to communicate with the upper OSI layer and keep track of the various conversations that occur simultaneously. Ports are also the mechanism used to identify how other computers access services. When a TCP or UDP message is formed, the source and destination ports are included in the header information along with the source and destination IP addresses. This IP address and port number is called a socket; the IP address serves as the gateway to the computer and the port serves as the gateway to the actual protocol or service.

×：IP address

This is incorrect because the IP address does not tell the packet how to communicate with the service or protocol. The purpose of an IP address is to identify and address the location of a host or network interface. Each node in a network has a unique IP address. This information, along with the source and destination ports, make up a socket. The IP address tells the packet where to go, and the port indicates how to communicate with the appropriate service or protocol.

×：Port

The port is incorrect because it tells the packet only how to communicate with the appropriate service or protocol. It does not tell the packet where it should go. The IP address provides this information. Ports are communication endpoints used by IP protocols such as TCP and UDP. Ports are identified by a number.

×：Frame

Frame is incorrect because the term is used to refer to a datagram after the header and trailer have been given to the data link layer.

〇：TLS is an open community version of SSL.

Secure Sockets Layer (SSL) and Transport Layer Security (TLS) are cryptographic protocols used to protect communications by encrypting segments of a network connection. SSL is a proprietary protocol and TLS was developed by a standards body, making it an open community protocol.

×：TLS is an open community version of SSL. SSL is a proprietary protocol and TLS was developed by a standards body, making it an open community protocol. x: The SSL protocol can be modified by developers to extend its capabilities.

This is incorrect because SSL is a proprietary protocol developed by Netscape. This means that the technical community cannot easily interoperate and extend SSL to extend to its functionality.

×：SSL is an open community protocol while TLS is a proprietary protocol.

The meaning and matching are reversed.

×：SSL is an extended version and backward compatible with TLS.

Wrong, since TLS is actually more extensible than SSL and is not backward compatible with SSL.

〇：OSI reference model

The OSI reference model is a seven-layer classification of network communication. The concepts of application communication and session are separated, which would be clearly communicated based on the OSI reference model. Therefore, the correct answer is “OSI reference model.

×：TCP/IP model

The TCP/IP model is a layer design that is closer to the concept of a system than the OSI reference model; in the TCP/IP model, the application layer, presentation layer, and session layer of the OSI reference model are represented by a single application layer.

×：Data link model

There is no such model.

×：Biba model

Biba model is one of the security models that indicates that data cannot be changed without permission.

〇：SMTP lacks proper authentication mechanisms.

Email spoofing is easy to perform if the SMTP lacks proper authentication mechanisms. An attacker can spoof the sender address of an e-mail by sending a Telnet command to port 25 of the mail server. The spammer uses e-mail spoofing to prevent himself from being identified.

×：The administrator forgot to configure a setting that prevents inbound SMTP connections for non-functioning domains.

If it is spoofed, the email sender is also spoofed. This can happen even if you prevent inbound SMTP connections for a domain.

×：Technically abolished by keyword filtering.

Filtering is not very effective against spoofing. Therefore, even if it is technically obsolete, it is unlikely to be the cause.

×：The blacklist function is not technically reliable.

If an email is spoofed, the sender of the email is also spoofed. This can happen even if the filtering function is not reliable.

Application firewalls target Layer 7 of the OSI. The main advantage of an application firewall is its ability to understand specific applications and protocols. Packets are not decrypted until Layer 6, so Layer 7 can see the entire packet. Other firewalls can only inspect the packet, not the payload. It can detect if an unwanted application or service is trying to bypass the firewall by using a protocol on an allowed port, or if the protocol is being used in a malicious manner.

The data link layer or Layer 2 of the OSI model adds a header and trailer to the packet to prepare the packet in binary format in local area network or wide area network technology for proper line transmission. Layer 2 is divided into two functional sublayers. The upper sublayer is logical link control (LLC), which is defined in the IEEE 802.2 specification. It communicates with the network layer above the data link layer. Below the LLC is the Media Access Control (MAC) sublayer, which specifies interfaces with the protocol requirements of the physical layer.

〇：3-tier architecture

The 3-tier architecture clearly distinguishes the three layers: the client has the user interface responsible for input and displaying results, and the server has the functional process logic responsible for data processing and data storage for accessing the database. The user interface role is generally handled by the front-end web server with which the user interacts. It can handle both static and cached dynamic content. The functional process logic is where requests are reformatted and processed. It is typically a dynamic content processing and generation level application server. Data storage is where sensitive data is held. It is the back-end database and holds both the data and the database management system software used to manage and provide access to the data.

×：2-tier architecture

Two-tier, or client/server, is incorrect because it describes an architecture in which a server serves one or more clients that request those services.

×：Screened Subnets

A screen-subnet architecture is for one firewall to protect one server (basically a one-tier architecture). The external, public-side firewall monitors requests from untrusted networks like the Internet. If one layer, the only firewall, is compromised, an attacker can access sensitive data residing on the server with relative ease.

×：Public and Private DNS Zones

Separating DNS servers into public and private servers provides protection, but this is not the actual architecture.

Carrier Sense Multiple Access Collision Detection (CSMA / CD) is used for systems that can transmit and receive simultaneously, such as Ethernet. If two clients listen at the same time and make sure the line is clear, both may transmit at the same time, causing a collision. Collision Detection (CD) is added to solve this scenario. The client checks to see if the line is idle and transmits if it is idle. If in use, they wait for a random time (milliseconds). During transmission, they monitor the network and if more input is received than transmitted, another client is also transmitting and sends a jam signal instructing other nodes to stop transmitting, wait a random time and then start transmitting again.

Diameter is an authentication protocol that implements the AAA (Authentication, Authorization, Accounting) service, the successor to RADIUS. This can cause performance degradation and data loss. This can lead to performance degradation and data loss.