To Memorize Flashcards
SSH
port 22 Secure Shell
Protocol allows secure remote admin of Linux servers and network equipment through text console. Uses public key cryptography. Pw and transmissions after login are encrypted.
TELNET
23, TELNET TCP
Legacy protocol being replaced by SSH. Allows remote admin of network devices through a text-based console. No encryption. Server/device listens for connection on port 23.
DNS
53 Domain Name Service
Used in translating fully qualified domain names to IP addresses. Decentralized hierarchical database used for resolving fully qualified domain names to IP addresses.
SMTP
Simple Mail Transport Protocol (tcp 25)
Protocol used to deliver emails to a destination mail server.
SFTP
22, Secure File Transfer Protocol, tcp
File transfer protocol that uses SSH. When SSH is installed on Linux, SFTP is automatically enabled to transfer files. Command is often scp (secure copy protocol). Since it uses SSH it awaits incoming connections on port 22.
FTP
File Transfer Protocol-20, 21 (tcp)
Legacy file-sharing protocol still commonly used. Being replaced with SFTP; SFTP offers encryption.
- Control Channel/Data Channel.
- Active Mode/Passive mode
- Control Channel listens for requests on TCP port 21.
- Sends data on port 20.
- Can cause issues at client firewall/NAT because server sends to port above 1023, from port 20….passive mode alleviates.
TFTP
69-Trivial File Transfer Protocol
TFTP server listens for requests on 69. Used to boot computers over the network with the Preboot Execution Environment (PXE). Also used to transfer software images for network devices (routers, switches) during software upgrades. No security, authentication.
DHCP
(67, 68) Dynamic Host Configuration Protocol UDP
Provides automatic configuration of IP addresses, subnet masks, and options such as Domain Name Server (DNS) servers and the remote gateway to network devices.
- operates in connectionless state.
- DHCP server listens for client requests on 67.
- CLIENTS send initial request FROM 68.
- SERVER responds, it to client port 68 from server port 67.
HTTP
80, Hyper Text Transfer Prot. TCP
Web page requests, web element requests. Web crawlers and mobile apps use 80 and http. Server listens on port 80.
Port 80
HTTP, Hyper Text Transfer Prot. TCP
Web page requests, web element requests. Web crawlers and mobile apps use 80 and http. Server listens on port 80.
HTTPS
Hyptertext Transfer Protocol. 443.
Provides same functionality as HTTP but also allows for the encryption of these transfers via a Secure Socket Layer.
Private key must be imported into the web server from a mutually trusted source.
Port 443
HTTPS, Hyptertext Transfer Protocol. TCP
Functionality of HTTP but also allows for encryption with Secure Socket Layer.
Private key must be imported into the web server from a mutually trusted source.
SNMP
161, Simple Network Management Prot
Used for the management of servers and network devices. Can collect data on memory, CPU, and bandwidth. Works with NMS network management station.
Port 161
SNMP, Simple Network Management Prot
Used for the management of servers and network devices. Can collect data on memory, CPU, and bandwidth. Works with NMS network management station.
What application uses tcp/3389?
RDP, Remote Desktop Protocol
MS protocol used for connecting to another Microsoft computer or server for remote admin.
RDP
3389, Remote Desktop Protocol, tcp
MS protocol used for connecting to another Microsoft computer or server for remote admin.
NTP
Network Time Protocol, 123, udp
Optimized for synchronizing clocks between computers over the Internet.
What is on udp/123?
NTP Network Time Protocol
Synchronizes clocks between devices
Automatic updates
What applications uses tcp/5060 and tcp/5061?
SIP Session Initiation Protocol. Used for VoIP service.
POP3 protocol?
TCP/110
Tcp/110
POP3
IMAP4 protcol?
143 tcp
What app uses tcp/143?
IMAP4
What is LDAP?
Lightweight Directory Access protocol
Store and retrieve network info.
Whats on tcp/389?
LDAP