Protocols Flashcards
TCP
Transmission Control Protocol
UDP
User Datagram Protocol
ICMP
Internet Control Message Protocol
nc
The Netcat (nc) command is a command-line utility for reading and writing data between two computer networks.
nc -l
nc in listening mode (-l flag)
nc -n
The -n flag means to disable DNS or service lookups.
Netcat
Is a simple yet powerful networking command-line tool used for performing any operation in Linux related to TCP, UDP, or UNIX-domain sockets. Netcat can be used for port scanning, port redirection, and as a port listener (for incoming connections); it can also be used to open remote connections and so many other things. Besides, you can use it as a backdoor to gain access to a target server.
FTP
File Transfer Protocol
The lack of what means that all Telnet communication is in plaintext?
Encryption
What communications model does FTP use?
client-server
What’s the standard FTP port?
21
NFS
Network File System
RPC
Remote Procedure Call (RPC) that answers a client request to mount a file system
Daemon
computer program that runs as a background process, rather than being under the direct control of an interactive user
What is Enumeration?
Enumeration is defined as “a process which establishes an active connection to the target hosts to discover potential attack vectors in the system, and the same can be used for further exploitation of the system.”
NFS-Common
It is important to have this package installed on any machine that uses NFS, either as client or server. It includes programs such as: lockd, statd, showmount, nfsstat, gssd, idmapd and mount.nfs. Primarily, we are concerned with “showmount” and “mount.nfs” as these are going to be most useful to us when it comes to extracting information from the NFS share.
What does NFS stand for?
Network File System
What protocol does NFS use to communicate between the server and client?
RPC Remote Procedure Call is a software communication protocol that one program can use to request a service from a program located in another computer on a network without having to understand the network’s details.
URL
Uniform Resource Locator
HTTP
Hyper Text Transfer Protocol
HTTPS
Hyper Text Transfer Protocol Secure
Plaintext
Data before encryption or hashing, often text but not always as it could be a photograph or other file instead.
Encoding
This is NOT a form of encryption, just a form of data representation like base64 or hexadecimal. Immediately reversible.
Hash
A hash is the output of a hash function. Hashing can also be used as a verb, “to hash”, meaning to produce the hash value of some data.
Brute force
Attacking cryptography by trying every different password or every different key
Cryptanalysis
Attacking cryptography by finding a weakness in the underlying math.
What is Caching?
In computing, a cache is a high-speed data storage layer which stores a subset of data, typically transient in nature, so that future requests for that data are served up faster than is possible by accessing the data’s primary storage location. Caching allows you to efficiently reuse previously retrieved or computed data.
Cookies
Computer cookies are small files, often including unique identifiers that web servers send to browsers. These cookies then can be sent back to the server each time your browser requests a new page. It’s a way for a website to remember you, your preferences, and your habits online.
What is SMTP?
SMTP stands for “Simple Mail Transfer Protocol”. It is utilized to handle the sending of emails. In order to support email services, a protocol pair is required, comprising SMTP and POP/IMAP. Together they allow the user to send outgoing mail and retrieve incoming mail, respectively.
What 3 Basic functions does an SMTP server perform?
- It verifies who is sending emails through the SMTP server.
- It sends the outgoing mail
- If the outgoing mail can’t be delivered it sends the message back to the sender
What does POP stand for?
Post Office Protocol
What does IMAP stand for?
Internet Message Access Protocol
