Twisted-Pair
Ethernet cables connect devices in an Ethernet network. Cables enable the transfer of wired data between devices.
Ethernet cables are categorized as Cat 4, Cat 5, Cat 6, and so on.
All Ethernet cables are twisted. The cable shielding protects the cable from interference. Network cables typically come in two basic types:
UTP
Unshielded Twisted Pair (UTP) is commonly used between a system and wall.
It is also used for desktop communication applications.
STP
Shielded Twisted Pair (STP):
Use STP cables for high-speed networks. High-speed networks such as 10 GbE are more sensitive to electromagnetic interference (EMI). Items such as motors, generators, and air conditioners that are near they system can cause EMI. A metallic substance shields STP. An additional metal foil wraps each set of twisted wire pairs together.
OCP
The OCP NIC card supports OCP 3.0.
NIC 포트는 OCP 카드에 통합되어 있으며, 해당 카드는 시스템 보드에 직접 연결됩니다.
IP Addressing
IPv4
In IP version 4 (IPv4), the network and host use a 32-bit IP address for identity.
Each number of the address is an 8 bits.
✅ Class A
범위: 1.0.0.0 ~ 126.255.255.255
기본 넷마스크: 255.0.0.0 (/8)
✅ Class B
범위: 128.0.0.0 ~ 191.255.255.255
기본 넷마스크: 255.255.0.0 (/16)
✅ Class C
범위: 192.0.0.0 ~ 223.255.255.255
기본 넷마스크: 255.255.255.0 (/24)
IPv6
IPv6 uses 128 binary bits to create a single unique address on the network.
NAT
사설 네트워크가 인터넷에 연결되기 위해서는 반드시 NAT(Network Address Translation) 게이트웨이를 사용해야 합니다.
DHCP
The Dynamic Host Configuration Protocol (DHCP) dynamically assigns IP addresses to devices on the network. It also assigns subnet masks, default gateways, and other parameters.
ARP
Address Resolution Protocol (ARP) maps an IP address to a physical machine or Media Access Control (MAC) address.
DNS
The Domain Name System (DNS) maps domain names to the numerical IP addresses needed for locating and identifying system services and devices.
NTP
Network Time Protocol (NTP) is used to unify system clocks to a single source.
NTP relies on Coordinated Universal Time (UTC) to calculate local time regardless of the time zone.
Email Exchange Service Protocols
Post Office Protocol (POP)
retrieves email information from an email server exchange and routes the email to an email client.
Simple Mail Transfer Protocol (SMTP)
sends email messages from an email client to an email server exchange application.
Internet Message Access Protocol (IMAP)
retrieves email information about a remote web server from a local email client.
SMTP → 📤 메일 보내는 용도
POP → 📥 메일 받아서 로컬로 저장
IMAP → 🔄 메일을 서버에 두고 동기화하며 사용
File Transfer Services
The File Transfer Protocol (FTP)
is a network protocol that is built on a client/server architecture. The architecture is to transfer files between a client and a server.
Secure File Transfer Protocol (SFTP)
is a secure FTP protocol that sends files over secure shell (SSH), providing a high level of protection for file transfers. Users can access, transfer, and manage files on a remote system.
The Trivial File Transfer Protocol (TFTP)
is an Internet software utility that is used for file transfer. TFTP is simpler to use than the File Transfer Protocol (FTP), but less capable.
The Hypertext Transfer Protocol (HTTP)
is used for transferring files on the World Wide Web. Files include text, graphics, audio, video, and other media.
