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.

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.

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.

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.

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

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

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.

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.

There are many different types of distributed denial of service (DDoS) attacks; there is no IPSec flood; UDP flood, SYN flood, and MAC flood are all distributed denial of service (DDoS) attacks.

A captive portal is a mechanism that restricts communication with the outside world until user authentication, user registration, and user consent are performed when a terminal connects to the network.

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.

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：Teardrop

Teardrop is an attack to bring a system to a halt by forging the offset of IP packets when they are returned before splitting.

×：Fraggle attack

Fraggle attack is an attack that uses the CHARGEN function to generate an appropriate string.

×：CHARGEN attack

There is no attack with such a name.

×：War Driving

Wardriving is the act of driving around a city looking for vulnerable wireless LAN access points.

Onion routing is characterized by multiple layers of encryption because encryption is applied each time it passes through a router. However, there is no security feature at the final router because all encryption is decrypted at the final point of the router and becomes plaintext.

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.

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.

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.

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.

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.