Common Ports and the OSI Model Flashcards
1
Q
Telnet
A
- TCP/23 port
- Login to rdevices remotely.
- console access
- in the clear no secure Auth
2
Q
SSH -
A
Secure Shell
- TCp/22 port
- Encrypted
- Replacement for Telnet
3
Q
DNS
A
Domain Naming System
- UDP/53
- Resolves hostnames to IP address.
4
Q
SMTP
A
Simple Mail Transfer Protocol
- TCP/25
- Sends mail from one server to another.
- Sends mail from mobile device and email clients.
- Not used for receiving email (IMAP/POP3)
5
Q
SFTP
A
Secure File transfer Protocol
- TCP/22
- Uses SSH to transfer files.
- Resuming interrupted transfers, directy listings, file removal.
- Encrypted information.
6
Q
FTP
A
File Transfer Protocol
- TCP/20 (active mode data)
- TCP/21 (control)
- Authenticates with a username and password.
Full-featured functionality (list add delete etc)
7
Q
TFTP -
A
Transfer File Protocol
- UDP/69
- Very simple FT app
- No authentication.
- Not used on production systems
8
Q
DHCP -
A
Dynamic Host Configuration Protocol
- UDP/67 and 68.
- Requires a DHCP server (server, appliance, integrated into a small office home office router, etc)
- Dynamic/pooled ip address are assigned in real time from a pool.
- Each system is given a lease and must renew at set intervals.
- DHCP reservation (addresses are assigned by MAC address in the DHCP server)
9
Q
HTTP and HTTPS
A
Hypertext Transfer Protocol
- TCP/80 (HTTP
- TCP/443 (HTTPS)
- Communication in the browser and by other apps.
- In the clear or encrypted.
- Supported by nearly all web servers and clients.
10
Q
SNMP -
A
Simple Network Management Protocol
- UDP/161
- Gathers statistics from network devices. - v1 - The original
- Structured tables
- in-the-clear - v2 - a good step ahead
- Data type enhancements
- Bulk transfers
- Still in-the-clear - v3 - A secure standard
- Message integrity
- Authentication
- Encryption.
11
Q
RDP -
A
Remote Desktop Protocol
- TCP/3389
- Share a desktop from a remote location.
- Remote Desktop Services on many Windows versions
- Can connect to an entire desktop or just an app.
- Clients for Windows, MACOs, Linux, Unix, iPhone and others.
12
Q
NTP
A
Network Time Protocol
- UDP/123
- Switches, routers, firewalls, servers, workstations
- Every device has it’s own clock - Synchronizing clocks becomes critical
- Log files, auth information, outage details - Automatic updates
- No flashing 12:00 lights - Very accurate
- Accuracy better than 1ms
13
Q
SIP
A
Session Initiation Protocol
- TCP/5061-5061
- Setup and manage VoIP sessions
- Call, ring, hangup - Extend voice comms
- Video conferencing
- Instant messaging
- File transfer
- etc
14
Q
SMB
A
Server Message Block
- TCP/445 (NetBIOS-less)
- Protocol used by Microsoft Windows
- File sharing, print sharing
- Allso called CIFS (Common Internet File System)
15
Q
POP/IMAP
A
- Receives emails from an email server
POP3 - Post office Protocol v3
- TCP/110
- Basic mail transfer functionality
IMAP4 - Internet Message Access Protocol v4
- TCP/143
- Includes management of email inbox from multiple clients