Jeremy's IT Lab CCNA TCP & UDP Day 30

[...] = TCP port 110

POP3

[...] = TCP port 20

FTP data

[...] = TCP port 21

FTP control

[...] = TCP port 22

SSH

[...] = TCP port 23

Telnet

[...] = TCP port 25

SMTP

[...] = TCP port 443

HTTPS

[...] = TCP port 80

HTTP

[...] = TCP/UDP port 53

DNS

[...] = UDP port 161

SNMP agent

[...] = UDP port 162

SNMP manager

[...] = UDP port 514

Syslog

[...] = UDP port 67

DHCP server

[...] = UDP port 68

DHCP client

[...] = UDP port 69

TFTP

[TCP/UDP] has less overhead.

UDP

[TCP/UDP] is connection-oriented.

TCP

[TCP/UDP] is connectionless.

UDP

[TCP/UDP] provides data sequencing.

TCP

[TCP/UDP] provides error recovery.

TCP

[TCP/UDP] provides flow control.

TCP

[TCP/UDP] provides reliable data transfer.

TCP

DHCP client = [...] port 68

UDP

DHCP client = UDP port [...]

68

DHCP server = [...] port 67

UDP

DHCP server = UDP port [...]

67

DNS = [...] port 53

TCP/UDP

DNS = TCP/UDP port [...]

53

For applications like real-time voice and video, [TCP/UDP] is preferred.

UDP

For applications that require reliable communications, [TCP/UDP] is preferred.

TCP

FTP control = [...] port 21

TCP

FTP control = TCP port [...]

21

FTP data = [...] port 20

TCP

FTP data = TCP port [...]

20

HTTP = [...] port 80

TCP

HTTP = TCP port [...]

80

HTTPS = [...] port 443

TCP

HTTPS = TCP port [...]

443

Layer 4 ephemeral port range (according to IANA):

49152 - 65535

Layer 4 registered port range (according to IANA):

1024 - 49151

Layer 4 well-known port range (according to IANA):

0 - 1023

POP3 = [...] port 110

TCP

POP3 = TCP port [...]

110

SMTP = [...] port 25

TCP

SMTP = TCP port [...]

25

SNMP agent = [...] port 161

UDP

SNMP agent = UDP port [...]

161

SNMP manager = [...] port 162

UDP

SNMP manager = UDP port [...]

162

SSH = [...] port 22

TCP

SSH = TCP port [...]

22

Syslog = [...] port 514

UDP

Syslog = UDP port [...]

514

TCP four-way handshake order of messages (terminating a connection):

FIN ->

<- ACK

<- FIN

ACK ->

TCP three-way handshake order of messages (establishing a connection):

SYN ->

<- SYN-ACK

ACK ->

TCP: [...] is used to indicate the sequence number of the next segment the host expects to receive.

Forward acknowledgement

TCP: A '[...]' is used to dynamically adjust how large the window size is.

sliding window

Telnet = [...] port 23

TCP

Telnet = TCP port [...]

23

TFTP = [...] port 69

UDP

TFTP = UDP port [...]

69

The Layer 4 [source/destination] port number is randomly selected by the host that initiates the data exchange.

source

The Layer 4 destination port number indicates the [...] Layer protocol.

Application

The TCP header [...] field is used for flow control.

window size

What are Layer 4 addresses?

Port numbers

What does TCP stand for?

Transmission Control Protocol

What does UDP stand for?

User Datagram Protocol