Original subtitles

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So what is a port and how does it work.

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Well in computer networks hardware connections are terminated physically wired or wireless in software

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a port within an operating system is a logical structure that identifies software specific process or

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service the ports are identified by 16 bit long numbers of each protocol an address combination.

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The most common protocols that use port numbers are the Transmission Control Protocol DCP and the user

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data Graham protocol UDP.

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Now the port number is always associated with a host IP address and its communication protocol type

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completes the destination or source network address of a message in certain port numbers are used for

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specific service.

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For example port 80 is used by HDP port for 4 3 is used by to be yes.

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Protocol so then this way the package can be easily transmitted to the running application the most

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commonly used ports are ports one through 10 24 and other ports can be specified to a particular application

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the most used default ports so below are the most commonly used default ports in the names of the services

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that use them.

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Now it's important to remember these ports know them well is because we can understand what the systems

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are in the target network when we're scanning.

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So according to the port scan results we can plan the next step or if there are services that we know

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are used within the target network we can scan directly for these services and then finish the scanning

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process without getting caught in the security systems so if Port 21 is open FTB services available

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in a port 53 is open DNS services available if Port 1 10 is open there is an S MTV service which means

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that mail service is up and running FTB is 21 as h 22 telnet it is always 23 S.M. T.P. 25 DNS UDP 53

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age GDP 80 pop 3 1 10 net bios 1 3 9 I'm at 143 S&P UDP 1 6 1 SMB Microsoft DNS UDP 4 4 5 RSA age 5

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1 4 VM where 9 0 2 M.S. Eskew 0 1 4 3 3 Oracle D.B. 15 20 one my ASCII Well 33 06 RTP 33 89 VA NC fifty

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nine hundred proxy application servers 80 80 in 1881.