Chapter 9: TCP/IP Applications Flashcards
Describe the TCP three-way handshake.
client -> synchronize -> server
client acknowledge -> server
Describe how a TCP session closes.
client acknowledge>server
client ->finished acknowledge -> server
client<- server
What ports does DHCP work on?
port 67 is used to send data to server
port 68 servers use to send data to DHCP clients
What port does NTP/SNTP use?
port 123
Describe TFTP.
uses UDP, no data proection
-uses port 69
Describe ICMP.
Layer 3 to deliver connectionless packets
Describe IGMP
Internet Group management protocol
used for multicasting
-particular multicast assigned to a 224.0.0.0/4
-hosts want to receive tell upstream router that they do.
What is a port number?
- 16 bit value between 0 and 65535
- 0 to 1023 are well known port numbers and reserves
- 1024-49151: registered ports
- 49,152 -65635: dynamic or private port numbers
What is a socket/endpoint?
session that is stored in RAM
-netstat -n shows you the endpoint
what command shows all listening ports?
netstat -an
What command shows the process id
netstat -ano
what tels you the name of the running program
netstat -G
What port does HTTPS use?
443
What is TLS
Transport Layer Security
What port does telnet use?
23, TCP
Describe rlogin.
- can configure to login automatically interactively
- only connects to unix hosts
- port 513
describe remote shell(RSH).
single commands to remote server
- easily integrated into a script
- port 514
describe Remote Copy Protocol(RCP)
- copy files to and from remote server
- can be used in scripts
- port 514
Describe SMTP.
- used to send email
- uses port 25
- used by clients to send messages
Describe POP3
- receive email from SMTP servers
- port 110
Describe IMAP4.
- Retrieves email from email server
- port 143
- can search through messages
- folders.
Describe sendmail.
-used on Linux and UNIX and only uses SMTP
Describe Microsoft Exchange Server.
- only runs on windows
- SMTP and POP3 in one package.
Describe FTP.
uses ports 21 and 20
- not secure because data transfers aren’t encrypted
- passive FTP only uses port 21
Describe active FTP
-doesn’t work if you use NAT
Describe passive FTP
- server doesn’t use port 20.
- client sends request on port 21
- server sends back random port # tells client which port its listening to for data requests.
- client initiates all conversations, NAT router knows where to send the packet.
- client needs to expect this incoming data.
What port does HTTP use?
-TCP, port 80
What port does HTTPS use?
TCP, port 443,
What port does telnet use?
TCP port 23
What port does SSH use?
TCP, port 22
What port does SMTP use?
TCP port 25
What port does POP3 use?
TCP port 110
What port does IMAP4 use?
TCP port 143
What port does FTP use?
TCP port 20/21
What port does TFTP use?
UDP port 69
