What is APT?

apt is a folder dedicated to app documentation. It stands for AdvancedPackagingTool, a powerful package management tool, which can also be called a mechanism.

In GNU/Linux, packages are maintained in a variety of ways. For example, DebianGNU/Linux's dpkg (apt is the front end of dpkg), RedHat's RPM, and the tarball method, which is highly customizable and, in my opinion, not an orderly way of managing packages, will not be discussed in this article. If you are interested, you can also read about installing software the tarball way.

There are many ways to manage packages; I prefer the apt way, the lazy way. With this approach, users can easily obtain a wealth of software from a specified source and perform tasks such as installing, upgrading, and uninstalling it; even upgrading the entire system using apt.

DDOS protection approach?

1, DDoS network attack protection: when faced with a large number of SYNFlood, UDPFlood, DNSFlood, ICMPFlood attacks, can quickly block the source of the attack to ensure that normal business operations.

2, domain name resolution dysfunction disaster recovery: when the root domain and top-level domain servers fail to provide normal service, or even when all external authorized servers fail, a company's next-generation firewall DNS proxy system can still serve as a resolution island to provide normal domain name resolution services.

3. DNS security policy linkage: track and monitor the resolution requests of key domains/domains, and when abnormal situations occur, start the relevant security linkage measures, and only respond to normal domain name services.

4. DNS amplification attack protection: When there is an abnormal surge in traffic of an IP, IP analysis and security linkage measures are automatically activated to limit the speed of the IP and prune the response results to effectively prevent the DNS server from becoming a source of amplification attacks.

5. Multi-line traffic scheduling disaster recovery: For customers with multi-line outlets, different export policies can be configured.

6. Weak credentials awareness: When a legitimate user logs in to all kinds of application management systems through a weak password, it will be intelligently perceived and notify the security administrator of the existence of a weak password security risk, thus improving the security level of the account.

7. Vulnerability attack protection: When the attacker of the enterprise information assets for password violence enumeration or system vulnerability attacks can be quickly detected when the attack behavior, and the formation of effective defense.

8, botnet detection: when the organization's internal staff through instant messaging tools or e-mail received malware, malware and the outside world in the process of communication can be quickly detected, and thus effectively protect the organization's internal information from being leaked.

9, APT Directed Attack Detection: A company's next-generation firewall can effectively detect APT Directed Attacks and ZeroDay Attacks as well as malware in the process of transmission through a variety of traffic identification algorithms, thus rejecting APT attacks from thousands of miles away.

usg6315 firewall benefits?

×USB3.0

Managing applications: recognizing 6000+ applications, access control precision to application functions, e.g., distinguishing between WeChat text and voice. Application recognition is combined with intrusion detection, anti-virus, and content filtering to improve detection performance and accuracy.

Bandwidth: Based on the identification of business applications, the bandwidth used per user/IP can be managed to ensure the network experience of key services and key users. Control methods include: limiting the maximum bandwidth or guaranteeing the minimum bandwidth, applying policy routing, modifying application forwarding priority, etc.

Cloud management: the device initiates authentication and registration to the cloud management platform by itself, realizing plug-and-play and simplifying the network creation and startup

Remote service configuration management, equipment monitoring and fault management, realizing the cloud management of a large number of devices

Safety standards All-in-one: Integrates traditional firewall, VPN, intrusion prevention, anti-virus, data leakage prevention, bandwidth management, Anti-DDoS, URL filtering, anti-spam, etc., with global configuration view and integrated policy management

Invasion: Get the latest threat information in the first time, accurately detect and defend against attacks against vulnerabilities. It can protect against a variety of attacks against the web, including SQL injection attacks and cross-site scripting attacks, etc.

APT: Linkage with local/cloud sandboxes to detect and block malicious files

Encrypted traffic does not need to be decrypted, and linkage with CIS, the big data analytics platform, realizes the detection of threats to the encrypted traffic

Actively responds to the behavior of malicious scanning and conducts behavioral analysis through the CIS, the big data analytics platform, to analyze the behavioral analysis. Data analysis platform CIS for behavioral analysis, rapid discovery, record malicious behavior, to achieve real-time protection against enterprise threats

Cloud management: enterprise cloud applications can be fine-tuned and differentiated control, to meet the needs of enterprises to control the use of cloud applications by users.

Power supply AC100-240V; 60W

Exterior design 1U

Product dimensions 442×420×44mm

Product weight 5.8kg

Applicable environment Operating temperature:0-45℃

Storage temperature:-40-70℃

Operating humidity:5%- 95% (non-condensing)

Storage Humidity:5-95%

Other PerformanceExternal Storage:Optional, support M.2 card, 240GB

Warranty PolicyNational Warranty, Three Pack Service

What is a DDOS attack? What is its principle? What is its purpose? The more detailed the better! I'd like to thank you for your help.

The website's biggest headache is being attacked, and common server attacks are mainly of these types: port penetration, port penetration, password cracking, and DDOS attacks. Among them, DDOS is currently the most powerful and one of the most difficult to defend against attacks.

What is a DDOS attack?

The attacker forges a large number of legitimate requests to the server, taking up a large amount of network bandwidth and paralyzing the website, making it inaccessible. It is characterized by the fact that the cost of defense is much higher than the cost of attack. A hacker can easily launch a 10G or 100G attack, while the cost of defending against 10G or 100G is very high.

The DDOS attack was initially called the DOS (Denial of Service) attack, which is based on the principle that if you have a server and I have a PC, I will use my PC to send a lot of spam to your server to congest your network and increase your data processing burden, reducing the efficiency of the server's CPU and memory.

However, with the advancement of technology, one-to-one attacks like DOS are easy to defend against, and so DDOS-Distributed Denial of Service attacks were born. The principle is the same as DOS, but the difference is that DDOS attacks are many-to-one attacks, even up to tens of thousands of PCs attacking a server at the same time with a DOS attack, which ultimately paralyzes the attacked server.

Three common DDOS attacks

SYN/ACKFlood attack: the most classic and effective DDOS attack, which can kill all kinds of system network services. Mainly through the victim host to send a large number of forged source IP and source port SYN or ACK packets, resulting in the host's cache resources are exhausted or busy sending response packets to cause a denial of service, due to the source are forged so tracking is more difficult, the disadvantage is the implementation of a certain degree of difficulty, need to be supported by high-bandwidth zombie hosts.

TCP full-connection attack: this attack is designed to bypass the conventional firewall checks, in general, most conventional firewalls have the ability to filter TearDrop, Land and other DOS attacks, but for normal TCP connections are spared, do not know that many network service programs (eg: IIS, Apache and other Web servers) can accept a limited number of TCP connections. TCP connections are limited, once a large number of TCP connections, even if normal, will lead to very slow access to the site or even inaccessible, TCP full-connection attack is through a number of zombie hosts constantly with the victim server to establish a large number of TCP connections, until the server's memory and other resources are exhausted and dragged across, thus resulting in a denial of service, the characteristics of this attack is to bypass the general This kind of attack is characterized by bypassing the general firewall protection to achieve the purpose of the attack, the disadvantage is that you need to find a lot of zombie hosts, and because the zombie host's IP is exposed, so this kind of DDOS attack is easy to be traced.

Brush Script Attack: This attack is mainly designed for the existence of ASP, JSP, PHP, CGI and other script programs, and call MSSQLServer, MySQLServer, Oracle and other databases of the website system, characterized by the establishment of a normal TCP connection with the server, and constantly submit queries to the script program, lists, and other calls that consume a lot of database resources, a typical attack method that uses a small amount of resources to attack a large amount of resources.

How to defend against DDOS attacks?

Overall, you can start from three aspects: hardware, individual hosts, and the whole server system.

One of the hardware

1. Increase bandwidth

Bandwidth directly determines the ability to withstand the attack, increase the bandwidth hard protection is the theoretical optimal solution, as long as the bandwidth is greater than the attack on the traffic is not afraid of, but the cost is very high.

2, enhance the hardware configuration

In the network bandwidth guarantee under the premise, try to enhance the CPU, memory, hard disk, network card, routers, switches and other hardware facilities configuration, selection of high-profile, well-reputed products.

3. Hardware firewall

Place your server in a server room with a DDoS hardware firewall. Professional-grade firewalls usually have a cleaning and filtering function for abnormal traffic, and can combat SYN/ACK attacks, TCP full-connection attacks, brush script attacks, and other traffic-type DDoS attacks

The second, a single host

1, timely repair of system vulnerabilities, upgrade security patches.

2, close unnecessary services and ports, reduce unnecessary system add-ons and self-startup items, minimize the implementation of fewer processes in the server, change the mode of operation

3, iptables

4, strict control of account privileges, prohibit root logins, password logins, and change the default ports of commonly used services

three, The entire server system

1. Load balancing

Using load balancing to distribute requests to individual servers in a balanced manner reduces the burden on a single server.

2. CDN

CDN is a content distribution network built on top of the network, relying on edge servers deployed in various places, through the distribution of the central platform, scheduling and other functional modules, so that users can get the content they need in the vicinity of the center to reduce network congestion and improve the response speed of the user's access and hit rate, so CDN acceleration is also used in load balancing technology. Compared with the high defense hardware firewalls can not possibly carry down the limit of unlimited traffic, CDN is more sensible, multi-node sharing penetration traffic, most of the CDN nodes have 200G traffic protection, coupled with the protection of the hard defense, it can be said to be able to cope with the majority of DDoS attacks.

3. Distributed cluster defense

Distributed cluster defense is characterized by multiple IP addresses in each node server configuration, and each node can withstand not less than 10G DDoS attacks, such as a node attacked by the inability to provide services, the system will be based on the priority settings automatically switch to another node, and the attacker's packets are returned to all the sending points, so that the attack source becomes paralyzed.

How to prevent a fixed IP address from being attacked from the outside. I'm not sure how to do this, but I'm sure it's a good idea to do it.

Attacks cannot be prevented.

There are many different types of attacks, and there are also different ways to defend against them. For traffic-type attacks, you can buy the operator's DDOS protection services. For WEB site attacks, you can deploy WAF, IPS and so on. Traditional attacks can use firewall defense. Defense of APT attacks, you need to strengthen the operation audit, log audit and so on.