S4-Ports and Protocols Flashcards
(63 cards)
What is a Port?
A logical opening in a computer that represents a service or application.
What Are the 3 groups of ports and their numbered ranges?
-Well-known (0 to 1,023)
- registered (1,024 to 49,151)
- Ephemeral (49,152 to 65,535)
What is IANA
“Internet Assigned Numbers Authority”
Well known ports and Reserved ports are registered with IANA
Ephemeral Ports
Temporary ports that are opened for a small period of time within a predefined range of ports.
What are the sizes for TCP and UDP Packet headers?
UDP = 8b
TCP = 20-60b
TCP
“Transfer Control Protocol”
fundamental protocol that consists of a set of rules that govern data exchange
what is a DDoS attack?
“Distributed Denial of Service”
A network of compromised computers is used to generate a significant amount of traffic.
Ping of Death
An attacker exploits a vulnerability to send malformed or oversized packets using ICMP.
ICMP
“Internet Control Message Protocol”
network layer protocol used to diagnose network related issues and send information to a host about network problems.
What are times when ICMP can be used?
- Indicating when a host or service is unreachable
- Report when a packet’s time to live has expired
- Router Buffer issues
What is the Max size of an IP packet?
65,535 bytes
What protocol/service uses port 80?
“Hypertext Transfer Protocol”(HTTP)
What is HTTP
“Hypertext Transfer Protocol”(HTTP)
- web browsing protocol
- data is sent in plain text
- not secure
What protocol/service uses port 443?
“Hypertext Transfer Protocol Secure” (HTTPS)
What is HTTPS
secure web browsing protocol that encrypts data by sending it down an SSL or TLS tunnel.
What are the three Main email protocols?
- SMTP
- POP3
- IMAP
SMTP
“Simple mail transfer protocol”
- Standard email protocol
- operates over Port 25
- used to transmit outbound emails
- Send only
- insecure (plain text)
SMTPS
SMTP that uses SSL or TLS to encrypt sent data.
What protocol/service uses port 25?
SMTP
What protocol/service uses ports 465 or 587?
SMTPS
POP3
“Post Office Protocol”
- used to receive/download emails from server to client
- operates over Port 110
- insecure protocol
What protocol/service uses port 110?
POP3
What protocol/service uses port 995?
POP3S
IMAP
“Internet Message Access Protocol”
- Allows users to manage emails directly on the email server
- uses Port 143
- Receives emails
- Insecure