ports to know for network exam

One, what is the port. Before we start talking about ports, let's talk about what port is. Often heard on the network "My host opened a number of port, will not be invaded AH." "or" it would be safer to open that port. Again, my service should correspond to what Port AH. Oh It's amazing. How a host has so many strange port on it. What's the effect of this port?Because the service features of each

Network Engineer Examination is the National computer technology and software level examination of an intermediate qualification examination, through the examination of qualified personnel in accordance with the requirements of the application Department of network system planning, design and installation of network equipment and hardware debugging work, can carr

51cto college specially sorted out "2014 network administrator-exam exercise Questions and Answers" in the soft exam preparation season to help schools pass smoothly! For more software proficiency test counseling and questions, please pay attention to the 51cto college-soft exam classification! View summary:Exercise q

Hadoop-definitions of Computer Network PortsPort Introduction The ports described in this article are all logical ports, which refer to the ports in the TCP/IP protocol. The port number ranges from 0 to 65535, for example, port 80 used to browse Web Services, port 21 for the FTP service. Here we will introduce the logi

In network technology, port has two meanings: one is physical port, for example, ADSL modem, Hub, switch, router is used to connect other network equipment interface, such as RJ-45 port, SC port and so on. The second is the logical port, which generally refers to the port in the TCP/IP protocol. The port number ranges from 0 to 65535, for example, port 80 used to browse Web Services, port 21 for the FTP ser

know that a host with an IP address can provide many services, such as Web services, FTP services, and SMTP services. These services can be implemented by one IP address. So how does a host distinguish between different network services? Obviously, we cannot only rely on IP addresses. In fact, we use a combination of IP addresses and ports to differentiate diffe

Network Engineer Examination is the National computer technology and software level examination of an intermediate qualification examination, through the examination of qualified personnel in accordance with the requirements of the application Department of network system planning, design and installation of network equipment and hardware debugging work, can carr

Network Engineer Examination is the National computer technology and software level examination of an intermediate qualification examination, through the examination of qualified personnel in accordance with the requirements of the application Department of network system planning, design and installation of network equipment and hardware debugging work, can carr

cannot be found in the bridge table of the bridge A, B, C, and D during the whole forwarding process, that is, these bridges do not know which port to forward the frame. When bridge A receives A unicast frame from the upstream network from the uplink port, it broadcasts the frame. After receiving the frame, bridge B and C also broadcast the frame, bridge D receives this unicast frame from bridge B and Brid

year in the first half of the soft test network engineer exam, whether you are ready to test or re-test, should know the second half of the registration began! Today we will talk about the network engineer registration of some relevant knowledge bar ~The network engineer is

The network software is composed of the client and the service side, and the server listens to the specified port to process the received data, and the client sends the data to the server-side listening port, and the data is processed by the server side, then the processing result is returned to the client.so how do we see on Linux what ports we are listening to, and which clients are connecting to my serve

Ipsecpol.exe to edit the registry. Before editing the registry, you must know how to restore the Registry in case of a problem. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:256986 Microsoft Windows registry descriptionNote: IPSec Filtering Rules may cause network programs to lose data and stop re

The so-called bind (BIND) refers to someone else connected I can only through the port I bind, equivalent to, I bought a mobile phone, others want to contact me, must know my mobile phone number, this time, I need to do? I need to plug in a phone card and fix a phone number so someone can contact me via this phone number. Phone card, fixed a phone number, similar to binding (BIND) process, binding (BIND) in order to fix a port number, the other

Precautions for binding ports to Linux Network Programming and port reuse (1) The so-called binding (bind) means that when someone connects to me, I can only use the port I bind, which is equivalent to buying a mobile phone. If someone else wants to contact me, he must know my mobile phone number, what should I do at this time? I need to plug in a phone card to

TCP: Transmission Control Protocol SYN: Request signal ACK: controlled command for acknowledgmentUDP: User Datagram ProtocolUDP belongs to a TIP/IP protocol family1. Turn on network port statusNetstat is a console command and is a very useful tool for monitoring TCP/IP networks, which can display routing tables, actual network connections, and status information for each

A few days ago, a switch cascade using a Cisco 2950 switch and a 100MB port of Tp-link 24 ports. Causes the Cascade ports on the Cisco 2950 device to be in use one day later, the next morning when the port shows err-disabled. The network is not working. How to deal with?To view the interface status:GX-SW-2950-01#SH Interfaces F0/2FASTETHERNET0/2 is off, line prot

The following article mainly takes the 80 port number as an example, if you want to know the other port number can also use the method 1, how to view the 80 port occupancy under Windows? What process is used? How to terminate and so on. The main use of the DOS tool under Windows, click "Start"-"Run", enter "cmd" and click the OK button to enter the DOS window, then run the following command: >netstat-aon | findstr " Proto Local address Foreign a

turning off unnecessary network ports can effectively protect network security, so do you know how to shut down these network ports ? We can enter the service and close the corresponding port in the following way. Turn of

connection to the outbound also has an impact, but is not reused), that is, as a service-side role, the client connected, the server actively closed the connection, time_wait state socket in the service side, The server quickly recycles the connection to that state. Thus, if the client is in a NAT network (multiple clients, the same IP egress network environment), if Tw_recycle is configured, it i

Lan exchange technology can also be called layer-2 Switch Exchange Technology, the content mainly includes the working principle of Layer 2 switching, network loops, and how to use the Spanning-Tree Protocol to solve Network loops, VLANs, and VTP technologies, this article mainly introduces the working principle of L2 switches and the dangers of network loops. Ot