email protocol ports

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

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

Windows has many open ports. When you access the Internet, network viruses and hackers can connect to your computer through these ports. To change your system to a copper wall, you should close these ports, mainly including TCP 135, 139, 445, 593,

List of common error reports for Linux email servers-Linux Enterprise applications-Linux server application information. For details, refer to the following section. Server 400 Error Report Q: 421 Server too busy A: Unable to connect because the

1. Close all INPUT FORWARD OUTPUT only for certain ports.Here is the command implementation:Iptables-p INPUT dropiptables-p FORWARD dropiptables-p OUTPUT DROPRe-use the commandIptables-l-NCheck to see if it's all set up.Such a setup, we are only

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

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

Network Protocol Model Analysis Network Protocol designers should not design a single, huge protocol to complete the details of all forms of communication regulations, but should divide the communication problems into multiple small problems, then a

[GO] Streaming Media protocol introduction (RTP/RTCP/RTSP/RTMP/MMS/HLS)http://blog.csdn.net/tttyd/article/details/12032357RTP reference Documentationrfc3550/rfc3551Real-time Transport Protocol) is a Transport layer protocol for multimedia traffic on

http://blog.csdn.net/tttyd/article/details/12032357RTPReference documentsrfc3550/rfc3551Real-time Transport Protocol) is a Transport layer protocol for multimedia traffic on the Internet. The RTP protocol details the standard packet format for