Week1 Flashcards
Which firewall table is responsible for changing packet content?
Filter Table
Raw Table
Mangle Table
NAT Table
Mangle Table
The _____ in the Filter table is responsible for handling all traffic targeted at the host internal/inbound interface.
Output Chain
Forward Chain
Input Chain
Input Chain
The input chain is responsible for monitoring all inbound network traffic.
_______ allows the inside host with a local address to always use an inside global address.
Static Address Mapping
Dynamic Address Mapping
Network Address and Port Translation (NAPT)
NAPT allows a large number of hosts on the private network to use a small set of public IP addresses.
Static Address Mapping
Static mapping allows the inside host with a local address to always use an inside global address.
What is the equivalent of a postal letter’s “receiver name” in electronic mail?
Network Prefix
Port Number
Host IP Address
Port Number
____ is session layer protocol.
DNS
NTP
DHCP
RPC
RPC Session layer protocols include RPC, L2TP, etc. and therefore handle different operations than DNS, DHCP, and NTP.
In the OSI model, which layer works with MAC addresses?
Data Link Layer
Network Layer
Transport Layer
Data Link Layer - This is the layer that works with MAC addresses.
What type of address is used at the end host to identify the application thread that sent and received the packet?
MAC Address
IP Address
Process ID
Port Number
Process ID
A process ID is used at end host to identify the process that sent and received the packet, not for local networking.
The CIDR concept is designed for IPv4 to _______ .
remove subnet concepts
make old classful IP addresses invalid
address an IP address shortage issue
address an IP address shortage issue
If we have /16 as our CIDR network mask, how many C subnets we can have?
256
An ip (v6) address has ____bits.
128
Switch is present at which layer of the TCP/IP protocol stack?
Physical Layer
Application Layer
Network Layer
Data Link Layer
Data Link Layer
Switches are present at the data link layer. Routing functionality is present on a higher layer of the TCP/IP protocol.
For the URL www.1.asu.edu, what is top domain level?
1
www
edu
ASU
edu
16 bits of number are used to represent a port number, so how many TCP/ UDP ports are available?
16bits of number are used to represent a port number, so there can be 2^16 = 65536 ports. Port 0 is reserved and can not use by anyone, so 65535 is also considered right answer.
The routing table is for R2 in the example below. In R2, to forward a packet with destination IP of 20.250.140.30, what is the next hop?
- 0.0.2
- 0.0.3
- 0.0.4
S1
- 0.0.2
- 250.140.30 is within network 20.0.0.0/8, which matches the first entry of the routing table, and the next hop for that entry is 30.0.0.2.
Which port does the HTTP Server need to use when communicating with an HTTP Client using port 50000?
22
80
443
80 -
Correct
The client and server will, and should, use different port numbers when communicating with each other. An http server will always use port 80, but the client will use a random number.
Which layer links the network support layers and user support layers?
Data Link Layer
Transport Layer
Physical Layer
Transport Layer
Physical, data link and network layers are network support layers and session, presentation and application layers are user support layers.
Which layer is responsible for process to process delivery?
Data Link Layer
Transport Layer
Network Layer
The role of the Transport layer (Layer 4) is to establish a logical end to end connection between two systems in a network. The protocols used in Transport layer are TCP and UDP.
Which address identifies a process on a host?
Logical Address
Network Address
Port Address
Port Address
A port number is a way to identify a specific process to which an Internet or other network message is to be forwarded when it arrives at a server.
In the TCP/IP Model, when data is sent from device A to device B, what is the 4th layer to receive data at B?
Data Link Layer
Application Layer
Transport Layer
In the TCP/IP model, the 4th layer is the application layer. When data is sent from device A to device B, the 4th layer to receive data at B is an application layer.
The application layer provides the basis for what?
Email Services
Error Control
Frame Division
Email Services - SMTP is an application layer protocol and moves email on and across networks.
Which layer is used to deal with mechanical and electrical specifications?
Data Link Layer
Network Layer
Transport Layer
Physical Layer
Physical Layer -
This layer is the first layer of the OSI model and is responsible for physical and electrical specification.
Routers operate at which layer of the OSI model?
Physical Layer
Network Layer
Transport Layer
Network Layer
This layer is responsible for packet forwarding and routing.
There can be ___ public IP addresses for each host on the Internet.
Any number of (>0)
3
1
Less than 10
Any number of (>0)
One public IP address should be assigned to ___host.
2
0
More than 1
1
1 - One public IP address should be assigned to one host, while one private IP address can be assigned to multiple hosts. That’s the major difference between public IP and private IP.
