For details about how to identify the extended serial port-Linux general technology-Linux technology and application information when installing centos on a multi-serial motherboard, refer to the following section. I bought a multi-serial control board with Intel Atom D525 CPU. It is estimated that multiple serial ports are extended through the PCI-e bus. After CentOS is installed, you cannot identify the extended serial port automatically. How can th
Main Command: lsof netstat
Netstat-anpt | grep PID
After knowing the process number, you can use this method to view which network ports are being used by the current process
Run the lsof command to view the files opened by the process.
Lsof-P 2012 // What files are opened by a process whose process number is 2012 (all files in Linux). Generally, a server such as JBoss can see that it has opened many files.
Lsof-C Apache // files opened by th
650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/46/4F/wKiom1PxtLuT8uDNAA7b5gUf4EM726.bmp "title=" Three layer switch different VLAN interworking. bmp "alt=" Wkiom1pxtlut8udnaa7b5guf4em726.bmp "/> Purpose: Two three-layer switches hang different VLANs for interoperability, all ports are access portsAfter the configuration is complete, 10.86.3.50 can ping any networked IP that resides on the device.LSW4 configuration:#sysname Huawei#VLAN Batc
1. Port 21:Port Description: port 21 is mainly used for FTP (File Transfer Protocol) services.Suggestion: Some FTP servers can be used by hackers to log on anonymously. In addition, port 21 will be used by some Trojans, such as Blade Runner, FTP Trojan, Doly Trojan, and WebEx. If you do not set up an FTP server, we recommend that you disable port 21.Port 2 and port 23Port Description: port 23 is mainly used for Telnet (Remote logon) services.Suggestion: using the Telnet service, hackers can sear
the FTP server for uploading and downloading. The most common attacker is used to find the method to open the FTP server of anonymous. These servers have read/write directories. Ports opened by Doly Trojan, Fore, Invisible FTP, WebEx, WinCrash, and Blade Runner.
Port: 22
Service: Ssh
Note: The TCP Connection established by PcAnywhere to this port may be used to search for ssh. This service has many vulner
first, the basic concept
Lan:local Area Network's abbreviation, i.e. LANour computers and our routes are connected to this port .
Wan:wide Area network abbreviation, the WANthe network cable that the operator pulls in is connected to the mouth.
The Chinese name of the VLAN (virtual local area network) isVLANs are typically subdivided into several network segments logically in a local area network to form a VLAN. A local area network can be divided into more than n VLANs, so that VLANs cannot co
through the port.Why do you need the concept of ports? In the process of network communication, you need to uniquely identify the endpoints on both ends of the communication, that is, using ports to identify applications running on a host. If no port is introduced, it can only be identified by the process number. Process numbers are dynamically allocated by the system, and different systems use different p
1024 The following is reserved for the system, and from 1024-65535 is used by the userFor personal writing applications, try not to use a port number between 0 and 1024.1024 to 65535 we can program with. This is not a Linux rule, it is the socket rules.1, 0~1023, these ports have IANA allocation and control, if possible, the same port number is assigned to TCP, UDP and SCTP the same given service. such as the 80 port is given to the Web service2.1024~
sent until the connection is closed. Hacker uses IP spoofing to launch DoS attacks. Forge a UDP packet between two chargen servers. Similarly, the Fraggle DoS attack broadcasts a packet with a spoofed IP address to the port of the target address. The victim is overloaded to respond to the data.
Port: 21Service: ftpDescription: The port opened by the FTP server for uploading and downloading. The most common attacker is used to find the method to open the FTP server of anonymous. These servers
1. Check if the server port is occupied>lsof-i:80812. View all ports on the server>netstat-ntlp3. Check if the server is open for a portTCP port: >NETSTAT-NTPLUDP port: >NETSTAT-NUPLCommon parameters:-A (All) displays all options and does not show listen related by default-T (TCP) displays only TCP-related options-U (UDP) displays only UDP-related options-N refuses to display aliases, showing all numbers converted to numbers.-l list only service statu
downloading. The most common attacker is used to find the method to open the FTP server of anonymous. These servers have read/write directories. Ports opened by Doly Trojan, fore, invisible FTP, WebEx, WinCrash, and Blade Runner. Port: 22 Service: SSH note: the connection between TCP established by pcAnywhere and this port may be used to find ssh. This service has many vulnerabilities. If configured in a s
Dos attacks. Forge a UDP packet between two Chargen servers. Because the server is attempting to respond to unlimited round-trip data traffic between two servers, a chargen and Echo will cause the server to overload. Similarly Fraggle Dos attacks broadcast a packet with a spoofed victim IP to this port on the destination address, and the victim is overloaded to respond to this data.FTP The most common attackers are used to look for ways to open the "anonymous" FTP server. These servers have a r
name service" (NetBIOS Name Service ).
Port 139: port 139 is provided for "NetBIOS Session Service" and is mainly used to provide Windows file and printer sharing and SAMBA service in UNIX.
Port 143: port 143 is mainly used for "Internet Message Access Protocol" V2 (Internet Message Access Protocol (IMAP ).
Port 161: port 161 is used for "Simple Network Management Protocol" (SNMP ).
Port 443: Port 43 is the Web browsing port, which is mainly used for HTTPS services. It is another type o
Vswitch Optical Fiber ports are divided into many types, and their functions are quite different. Here we will mainly introduce some basic knowledge about common optical fiber ports of vswitches. Cascade uses both common ports and special MDI-II ports. A straight-through cable should be used when the two
Currently, serial ports are commonly used data transmission channels between computer and external control systems in various control systems for laboratory and industrial applications. As serial communication is convenient and easy to use, it is widely used. However, the use of serial communication imposes restrictions on real-time performance, speed, and data size. While the computer's parallel port transfers data at a time by eight (one byte) or mo
The emergence of a multi-Wan port Broadband Router increases the total bandwidth available to users and the network is more stable. Therefore, the key to "more ports" is today.
After the development of the market, the market will face fierce competition. For Internet cafes and other users, how to achieve high-speed and stable access through low costs is the key to winning the competition, A multi-Wan port Broadband Router can make great contributions.
, Samsung's s3c2440 is a 32-bit ARM processor, and its 4GB address space is partitioned by peripherals, RAM, and so on:0x8000 1000 LED 8*8 dot matrix address0x4800 0000 ~ 0x6000 0000 SFR (Special Register) address space0x3800 1002 Keyboard Address0x3000 0000 ~ 0x3400 0000 SDRAM Space0x2000 0020 ~ 0x2000 002e IDE0x1900 0300 CS8900
Independent address (separate address): The IO address is separately addressed from the storage address, the I/O port address does not occupy the address range of th
Common ports management software commands
① Install software
The following uses RPM installation as an example:
[Root @ bsd01 ~] # Cd/usr/ports/archivers/RPM
[Root @ bsd01/usr/ports/archivers/RPM] # make install clean
A large number of temporary files are generated during software installation. These temporary files are recommended to be retained, but sometimes,
I. I/O portA port is the address of a register in an interface circuit that can be accessed directly by the CPU. Almost every peripheral is made from a register on a read-write device. The CPU sends commands to the registers in the interface circuit through these addresses, namely ports, to read the status and transmit the data. Peripheral registers, also known as "I/O ports", typically include: control reg
By default, Windows opens many service ports on our computers. Hackers often use these ports for intrusion. Therefore, understanding port knowledge will help us improve internet security.
First, let's take a look at what is a Port:
In network technology, a Port has two meanings: one is a physical Port, for example, ADSL Modem, Hub, switch, router and interfaces used to connect to other network devices, such
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