devkuma – Windows

Ports Used by Windows

kc@example.com (kc kim) — Mon, 01 Jan 2007 00:00:00 +0900

This is a list of ports used by Windows systems.

Port	Description
7	echo Echo
9	discard Discard; alias = sink null
13	daytime Daytime
17	qotd Quote of the day; alias = quote
19	chargen Character Generator; alias = ttyst source
20	ftp-data File Transfer (Default Data)
21	ftp File Transfer (Control)
23	telnet Telnet
25	smtp Simple Mail Transfer; alias = mail
42	nameserver Host Name Server; alias = nameserver
43	nicname Who Is; alias = nicname
53	domain Domain Name Server; alias = nameserver, dns
66	sqlnet Oracle SQLNET
67	bootpc DHCP/BOOTP Protocol Server
68	bootpc DHCP/BOOTP Protocol Server
69	tftp Trivial File Transfer
70	gopher Gopher
79	finger Finger
80	www WWW HTTP
90	Default WINS name server destination port
107	rtelnet Remote Telnet Service
108	snagas SNA Gateway Access Server
109	pop2 Post Office Protocol Version 2
110	pop3 Post Office Protocol Version 3
118	sqlserv SQL Service
119	nntp Network News Transfer Protocol; alias=usenet
123	ntp Network Time Protocol; alias=ntpd ntp
137	netbios-ns NetBIOS Name Service
138	netbios-dgm NetBIOS Datagram Service
139	netbios-ssn NetBIOS Session Service
143	IMAP
161	snmp SNMP; alias=snmp
162	snmptrap SNMPTRAP
177	xdmcp X Display Manager Control Protocol
178	nextstep Nextstep Window Server
194	irc Internet Relay Chat Server
443	SSL
445	SMB
1433	SQL
1761	SMS 2.0
3389	Terminal Client
5631	(TCP) pcanywhere
5632	(UDP) pcanywhere

Windows and UNIX-like Systems Use Different Line Break Characters

kc@example.com (kc kim) — Thu, 20 May 2021 10:07:24 +0900

Line Break Characters by OS

Windows and UNIX-like operating systems handle line breaks differently. The difference is in the newline characters: Windows uses CR+LF, while UNIX-like operating systems such as Linux use LF. It may be easier to understand this as the difference between \r\n and \n.

The symbols mean the following.

\r: CR (Carriage Return). Move to the beginning of the current line.
\n: LF (Line Feed). Move to the next line.

Line break characters by OS are as follows.

DOS (Windows): \r\n
UNIX or Linux: \n
Mac: \r, which by itself means CR+LF.

How to Solve Line Break Character Issues by OS

Because of this issue, text files written on Linux often do not display line breaks correctly when opened on Windows. Let’s look at ways to solve this problem.

Windows - WordPad

On Windows systems, there is a program called WordPad under Start - Accessories.

If you open a text file written on Linux with WordPad, the line breaks are displayed normally.

In this state, use the “Save As” feature. A window appears where you can specify the save path and file name. In the lower “Save as type” section, you can select “Text Document - MS-DOS format”.

If you select this and save the file, the line breaks are processed and saved as Windows CR+LF, creating a text document that can be used normally on Windows.

If this method still does not process the file correctly, handling it on Linux, where the problem started, is probably the fastest method.

UNIX-like OS - VIM

Open the target file with VIM.

In Linux VIM, you can freely convert Windows files to UNIX format and UNIX files to Windows format. First, convert a Windows file to UNIX format as follows.

:set ff=unix

Now just save the file. It is very simple.

Converting a UNIX file to Windows format is also simple.

:set ff=dos

Summary

If you cannot use this kind of editor, one option is to download the file from FTP in ASCII mode from the beginning so it is converted automatically. Finally, as a very simple tip for handling \r\n and \n, you can unconditionally replace \r\n with \n and then process only \n.

Windows Hyper-V

kc@example.com (kc kim) — Sun, 07 Mar 2021 02:08:48 +0900

What Is Virtualization?

In general, an OS runs on hardware such as memory and hard disks. By running that hardware as software, you can create another computer inside an OS.

Benefits of Virtualization

You can save space, energy, and cost by reducing the number of physical servers.
You can build different OS environments.
You can reduce the cost and time needed to prepare environments.

Drawbacks of Virtualization

Because overhead is added, applications that depend heavily on hardware may not work properly.

What Is Hyper-V?

Hyper-V is a virtualization technology provided by Microsoft.

Hyper-V Features

Hyper-V has two major characteristics.

It is a Windows Server feature.
- Because Microsoft provides it just like Windows, it is included with Windows Server, has no additional cost, and is simple to use.
It is hypervisor-based virtualization technology.
- Unlike host-based virtualization technology such as Virtual Server, it runs on a hypervisor in the same way as the management OS, so it operates faster than host-based virtualization.

Enable Hyper-V

To use Hyper-V, you must install and enable it first. Enable it through the page below.

Install Hyper-V on Windows 10 | Microsoft official site

Install CentOS on Hyper-V

Download the CentOS Installation File

CentOS Download

Download CentOS Stream 9 x86_64 from the link above.

Quickly Create a Virtual Machine for Installing CentOS on Hyper-V

Here, create a virtual machine with Quick Create.

Open Hyper-V and click “Quick Create…”.
When the “Create Virtual Machine” dialog appears, click “Local installation source (_L)”, then click the “Change installation source” button.
In the file selection window opened by “Change installation source”, select the CentOS .iso file downloaded earlier. Since you are not installing Windows, clear the “This virtual machine will run Windows” checkbox.
Click “More options” to show the “Name” and “Network” fields. Enter any name you want, then click “Create Virtual Machine”.
The screen changes to the virtual machine creation screen, and messages appear while it creates several items.
After a short wait, it finishes with the message “The virtual machine was created successfully.”

Create a New Virtual Machine for Installing CentOS on Hyper-V

Here, create a virtual machine by using New Virtual Machine.

Open Hyper-V and click “New…”.
Specify Name and Location: set a name and select the installation location. Here, the D drive is specified.
Specify Generation: select the desired generation. Here, proceed with the default Generation 1.
Assign Memory: the default is 1024 MB, but here it is changed to 4096 MB.
Configure Networking: select the connection setting to use.
Connect Virtual Hard Disk: configure the hardware. Here, only the size is set to 80 GB.
Installation Options: select options for the operating system to install. Here, select the CentOS .iso file from above.
Summary: the items selected above are summarized. Click the final “Finish” button to complete.

Install CentOS on Hyper-V

Now install CentOS on Hyper-V.

If you created the virtual machine with “Quick Create”, click the “Connect” button after the installation screen appears.
Or select the added virtual machine from the list and click “Connect”.
A black screen appears as shown below. Click “Start”.
Select “Install CentOS Stream 9”.
When the language selection screen appears, click “Continue”.
This is the configuration screen.
1. You must configure all items with warning marks before the “Begin Installation” button becomes active.
2. On the “Installation Summary” screen, click “Installation Destination”, select the disk to install to, and click “Done”.
3. On the “Installation Summary” screen, click “Root Password”, set the root account password, and click “Done”.
4. On the “Installation Summary” screen, click “User Creation”, set the user information, and click “Done”.
5. On the “Installation Summary” screen, click “Software Selection”, select the base environment, and click “Done”. Here, select “Minimal Install” because CLI will be used.
6. When all settings are complete, click “Begin Installation”.
Installation now proceeds.
When installation finishes with the message “Complete!”, click “Reboot System”.
After rebooting, you can confirm that login works with the account configured above.