Chapter 3 - TCP/IP Flashcards
What are the four layers to the DOD Model
Process/Application
Host to Host/Transportation
Internet
Network Access/Link Layer
In the DOD Model, what does the process/application layer include
Telnet FTP LPD SNMP TFTO SMTP NFS xWindow
In the DOD Model, what does the transportation layer include
TCP/UDP
In the DOD Model, what does the Internet layer include
IP
In the DOD Model, what does the network access layer include
Ethernet
Fast ethernet
tokken ring
fddi
What is telnet and what port does it use
Telnet is s terminal emulation protocol that essentially works like a virtual keyboard.
Everything is sent in clear text
Uses an 8 bit connection via UDP
What is SSH and what port does it use
Port 22
Much like telnet, it is used to issue commands to a remote computer, but everything is encrypted.
What is FTP and what port does it use
Used to transfer files between two machines.
Port 20 & 21
What is TFTP and what port does it use
Commonly used to boot via the network. Similar to FTP, but doesn’t allow directory browsing and sends much smaller blocks.
Port 69
What is SNMP and what port does it use
Used to collect and manipulate network info
A network management station periodically polls the devices on the network and can alert an admin of problems
Port 161 & 162
What is HTTP and what port does it use
Used to communicate between web browsers and servers
Port 80
What is HTTPS and what port does it use
Port 443
Secure version of HTTP; HTTP over SSL
What is NTP and what port does it use
Used to synchronize clocks on the network
Port 123
What is DNS and what port does it use
Used to resolve domain names to IP
Port 53
What is DHCP/BOOTP
Port 67 Server Port 68 Client
Assigns IP addresses to hosts on the LAN
BOOTP requires manually input of IP addresses
This uses UDP at layer 4
What is APIPA
Automatic Private IP Addressing is self configured to communicate without a DHCP server.
169.254.0.1 - 169.254.255.254
What is a Class A IP address
Network.Host.Host.Host Range: 0-127 First bit in the network address must be zero Max 126 networks (+1 for diagnostics) Max 16,777, 216 nodes Reserved 10.0.0.0-10.255.255.255
What is a Class B IP address
Range: 128-192
Network.Network.Host.Host
First bit of the first two bytes has to be 1.
16384 possible networks (2^14, 14 of the 16 possible bits)
65534 possible nodes
RESERVED: 172.16.0.0 - 172.31.255.255
What is a Class C IP address
Network.Network.Netowrk.Host Range 192- 223 First 2 bits of the first 3 bytes must be 1. 2, 097, 152 possible networks 254 possible nodes
What is a Class D ip address
Multicast address
Range 224-239
What is a class E IP address
Experimental
240-255
What is NAT
Used to translate an IP address to a public routable address.
Outline what TCP is
Breaks data into segments Assigns sequence to segments Retransmits lost segments Connection oriented Costly
Outline the structure of a TCP header
32 bit Sequence 32 Bit ACK 4 Bit Header length ? bit reserved ? bit flags 16 bit Window Size 16 bit checksum 16 bit urgent point Options Data 16 bit source port 16 bit destination port
