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.

〇：DNSSEC

DNSSEC is a set of extensions to the DNS that provide DNS clients (resolvers) with authentication of the origin of DNS data to reduce the threat of DNS poisoning, spoofing, and similar attack types. It is an Internet Engineering Task Force (IETF) specification for securing services.

×：Resource Record

DNS servers contain records that map hostnames to IP addresses, called resource records. The answer is incorrect. When a user’s computer needs to resolve a hostname to an IP address, it looks in its network configuration to find its DNS server. The computer then sends a request containing the hostname to the DNS server for resolution; the DNS server looks at its resource records, finds a record with this particular hostname, retrieves the address, and responds to the computer with the corresponding IP address.

×：Zone Transfer

Primary and secondary DNS servers synchronize their information via zone transfers. The answer is incorrect. After changes are made to the primary DNS server, these changes must be replicated to the secondary DNS server. It is important to configure the DNS servers so that zone transfers can take place between specific servers.

×：Resource Transfer

Equivalent to transferring DNS resource records, but the answer is incorrect.

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.

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

Point-to-Point Tunneling Protocol (PPTP) is a way to implement a virtual private network (VPN). It is Microsoft’s proprietary VPN protocol that operates at the data link layer of the OSI model; PPTP can only provide a single connection and can operate over a PPP connection.

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.

IEEE 802.11 is one of the wireless LAN standards established by IEEE.

A well-known port is a port number from 0 to 1023 that is reserved for standard services. There are three port number combinations. Well-known port numbers (0-1023) are port numbers officially registered with IANA. Registered port numbers (1024-49151) are port numbers that are officially registered with IANA. A dynamic/private port number (49152-65535) is a port number that is not officially registered with IANA.

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：Security

Voice over Internet Protocol (VoIP) refers to a transmission technology that delivers voice communications over an IP network; IP telephony uses technology that is similar to TCP/IP and therefore similar in its vulnerabilities. Voice systems are vulnerable to application manipulation and unauthorized administrative access. It is also vulnerable to denial of service attacks against gateway and network resources. Eavesdropping is also a concern since data traffic is transmitted in clear text unless encrypted.

The term security is a difficult answer to choose from because it has a very broad meaning. However, information security scriptures such as CISSP are persistent in saying that VoIP has vulnerabilities. Although this answer is a bit over the top in practical terms, it was made to educate the public, because depending on the creator’s intentions, this issue may arise.

×：Cost

Wrong, because cost is an advantage of VoIP; with VoIP’s, a company becomes a dedicated alternative to a separate network dedicated to data transmission and voice transmission. For telephony features such as conference calling, call forwarding, and automatic redialing are freed up in VoIP, which is open source, while companies that use traditional communications charge for VoIP.

×：Convergence

Wrong because convergence is the advantage of VoIP. Convergence means the integration of traditional IP networks with traditional analog telephone networks.

×：Flexibility

Wrong, because flexibility is an advantage of VoIP. The technology is very simple, easy and supports multiple calls over a single Internet broadband connection.

〇：VLAN

Virtual LANs (VLANs) allow logical isolation and grouping of computers based on resource requirements, security, or business needs, despite the standard physical location of the system. Computers in the same department configured on the same VLAN network can all receive the same broadcast messages, allowing all users to access the same types of resources regardless of their physical location.

×：Open Network Architecture  

Open network architecture is wrong because it describes the technology that can configure a network; the OSI model provides a framework for developing products that operate within an open network architecture.

×：Intranet

Incorrect because an intranet is a private network used by a company when it wants to use Internet and Web-based technologies in its internal network.

×：VAN  

Incorrect because a Value Added Network (VAN) is an electronic data interchange (EDI) infrastructure developed and maintained by a service bureau.

Computer worms are standalone malware computer programs that replicate themselves and spread to other computers. They typically operate at OSI reference layers 5-7.

VoIP uses UDP. It is real-time oriented, and it is probably better to lose one or two packets than to retransmit a few seconds later in a connectionless fashion.

〇：Softphones are safer than IP phones. 

IP softphones should be used with caution. A softphone is a software application that allows users to make calls via computer over the Internet. Replacing dedicated hardware, a softphone works like a traditional telephone. Skype is an example of a softphone application. Compared to hardware-based IP phones, softphones are more receptive to IP networks. However, softphones are no worse than other interactive Internet applications because they do not separate voice traffic from data, as IP phones do, and also because data-centric malware can more easily enter the network through softphones. network.

×：VoIP networks should be protected with the same security controls used on data networks.

The statement is incorrect because it correctly describes the security of an IP telephony network. an IP telephony network uses the same technology as a traditional IP network, which allows it to support voice applications. Therefore, IP telephony networks are susceptible to the same vulnerabilities as traditional IP networks and should be protected accordingly. This means that IP telephony networks should be designed to have adequate security.

×：As an endpoint, IP telephony can be a target of attack.

Incorrect because true: An IP phone on an IP telephony network is equivalent to a workstation on a data network in terms of vulnerability to attack. Thus, IP phones should be protected with many of the same security controls implemented on traditional workstations. For example, the default administrator password must be changed. Unnecessary remote access functions need to be disabled. Logging should be enabled and the firmware upgrade process should be secured.

×：The current Internet architecture in which voice is transmitted is more secure than physical phone lines.

True and therefore incorrect. In most cases, the current Internet architecture in which voice is transmitted is more secure than physical telephone lines. Physical phone lines provide a point-to-point connection, which is difficult to leverage over the software-based tunnels that make up the bulk of the Internet. This is an important factor to consider when protecting IP telephony networks because the network is now transmitting 2 valuable asset data and voice. It is not unusual for personal information, financial information, and other sensitive data to be spoken over the phone; intercepting this information over an IP telephony network is as easy as intercepting regular data. Currently voice traffic should also be encrypted.

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.

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.

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：LAND attack

A LAND attack is an attack that penetrates firewalls that block bad requests; it is similar to the Fraggle attack, but it sends a request to the firewall with the sender as the target of the attack. This is a blind spot because the firewall, which is supposed to protect the inside of the system, is used for the attack.

×：Teardrop

Teardrop is an attack that halts the system by forging the offset of IP packets before they are split.

×：Christmas Tree Attack

A Christmas tree attack is an attack in which a packet is sent with a number of flags (URG, ACK, PSH, RST, SYN, FIN) and the response is observed.

×：CHARGEN attack

CHARGEN (port 19) is a protocol that returns an appropriate string.

〇：Stateful Inspection

Stateful Inspection detects abnormal communication in which the request and response are linked and only the response is returned from a different server. Therefore, the correct answer is “Stateful Inspection.

×：Application Gateway

Commonly referred to as WAF, this is used when filtering is performed based on strings in telegrams, such as SQL injection.

×：Packet Filtering

Used for filtering by IP address or port.

×：Session Gateway

There is no such firewall category.