Midterm Switches and Routers Ch 1-5

How many collision domains are created when you segment a network with a 12-port switch?

12 - Each port on a switch creates its own collision domain

How many broadcast domains are created when you segment a network with a 12-port switch?

1 - A switch creates one broadcast domain (unless VLANs are configured)

Which statement is true with regard to a 12-port hub?

It includes one collision domain and one broadcast domain

With respect to the OSI model, which is the correct statement about PDU's?

A packet contains IP addresses (Layer 3)

The protocol data unit (PDU) de-encapsulation is completed in which order?

Bits, frames, packets, segments, data (Physical to Application layer)

Convert IP address 172.16.20.54 to binary

10101100.00010000.00010100.00110110

Ethernet hubs operate at layer , LAN switches work at layer, and Routers work at layer ___

1, 2, 3 (Physical, Data Link, Network)

What is a collection of many separate networks?

An internetwork

Match OSI Layer to PDU: Transport

Segment

Match OSI Layer to PDU: Data Link

Frame

Match OSI Layer to PDU: Physical

Bits

Match OSI Layer to PDU: Network

Packet

Match OSI Layer to Function: Transport

End to end connection

Match OSI Layer to Function: Data Link

Framing

Match OSI Layer to Function: Physical

Conversion to bits

Match OSI Layer to Function: Network

Routing

Which OSI layer was later subdivided into two layers?

Data Link (into LLC and MAC sublayers)

Which device operates at all layers of the OSI model?

Network host

What are the two types of fiber optic cables?

Multi-Mode and Single-Mode

What contention method does wired Ethernet use?

CSMA/CD (Carrier Sense Multiple Access with Collision Detection)

When can you NOT use full duplex?

With a connection from a host to a hub

When would you use a straight through cable?

With a connection from a host to a switch (unlike devices)

What cable connects to the console port of a router or switch?

Rollover cable

What two purposes does Ethernet protocol use physical addresses for?

To uniquely identify devices at layer 2 AND to allow communication between different devices on the same network

Convert hexadecimal 15 to decimal

21 (1×16 + 5)

What does UTP stand for?

Unshielded Twisted Pair

What does STP stand for?

Shielded Twisted Pair

What is the length of a MAC address?

48 bit (6 bytes) written in hexadecimal

Hub: How many collision and broadcast domains?

1 collision domain, 1 broadcast domain

Bridge: How many collision and broadcast domains?

2 collision domains, 1 broadcast domain

Switch: How many collision and broadcast domains?

4 collision domains, 1 broadcast domain (per the network diagram)

Router: How many collision and broadcast domains?

3 collision domains, 3 broadcast domains (per the network diagram)

What is the most common physical topology used in networking today?

Star topology

Are NGFWs considered third-generation firewall technology that provides inspection up to layer 4?

False - NGFWs inspect up to Layer 7

What is the function of a firewall?

To monitor and control the incoming and outgoing network traffic

Do VLANs break up collision domains?

False - VLANs break up broadcast domains, not collision domains

Switches break up ___ domains

Collision domains

What does CSMA/CD stand for?

Carrier sense multiple access with collision detection

Match OSI Layers: Layer 7

Application

Match OSI Layers: Layer 6

Presentation Layer

Match OSI Layers: Layer 5

Session

Match OSI Layers: Layer 4

Transport

Match OSI Layers: Layer 3

Network

Match OSI Layers: Layer 2

Data Link Layer

Match OSI Layers: Layer 1

Physical

What are the three layers of Cisco's three-layer hierarchical model?

Core, Distribution, Access

What does a socket comprise?

IP address and port number

What protocol finds the hardware address from a known IP address?

ARP (Address Resolution Protocol)

Which application protocol sets up a secure session similar to telnet?

SSH (Secure Shell)

If you use Telnet or FTP, what layer are you using to generate data?

Application layer

What layer in TCP/IP stack is equivalent to the Transport layer of OSI?

Host to Host layer

Describe TCP characteristics

Connection Oriented and Reliable

Describe UDP characteristics

Connection-less and Unreliable

How many layers does the DOD model have?

4 layers (condensed version of OSI's 7)

In an IP version 4 mask, what do one's represent?

Network address

In an IP version 4 mask, what do zero's represent?

Host address

Does DHCP assign MAC addresses?

False - DHCP does NOT assign MAC addresses (they are burned into NICs)

What does DNS resolve?

Host Names to IP Addresses

Are well-known ports 1023 and above?

False - Well-known ports are 0-1023; dynamic ports start at 1024

Is TCP un-sequenced, unreliable and connectionless?

False - TCP is sequenced, reliable, and connection-oriented

What statements are true about ICMP packets?

ICMP can provide hosts with information about network problems AND ICMP is encapsulated within IP datagrams

Multicast address definition

One to some, but not all devices

Unicast address definition

One to one device

Broadcast address definition

One to all devices

What does ping 127.0.0.1 test?

The TCP/IP stack on a network host (loopback address)

Which troubleshooting step confirms all other steps will succeed?

Ping a remote computer

Which class provides maximum of only 254 host addresses per network ID?

Class C

Is TCP connection-oriented and UDP connectionless-oriented?

True

Maximum IP addresses on subnet with 255.255.255.240 mask?

14 usable hosts (/28 mask = 16 addresses - 2)

How many bits to borrow for 29 subnets while maximizing hosts?

5 bits (2^5 = 32 subnets)

If host has address 172.16.45.30/30, what subnetwork does it belong to?

172.16.45.28 (/30 has block size of 4)

Server on subnet 192.168.19.32/29, router has first host, what IP for server?

192.168.19.35 255.255.255.248

198.13.70.200/26: Find subnet

198.13.70.192

198.13.70.200/26: Find 1st usable host

198.13.70.193

198.13.70.200/26: Find last usable host

198.13.70.254

198.13.70.200/26: Find broadcast address

198.13.70.255

198.241.68.166/30: Find subnet

198.241.68.164

198.241.68.166/30: Find 1st usable host

198.241.68.165

198.241.68.166/30: Find last usable host

198.241.68.166

198.241.68.166/30: Find broadcast address

198.241.68.167

88.248.235.250/27: Find subnet

88.248.235.224

88.248.235.250/27: Find 1st usable host

88.248.235.225

88.248.235.250/27: Find last usable host

88.248.235.254

88.248.235.250/27: Find broadcast address

88.248.235.255

55.110.67.205/16: Find subnet

55.110.0.0

55.110.67.205/16: Find 1st usable host

55.110.0.1

55.110.67.205/16: Find last usable host

55.110.255.254

55.110.67.205/16: Find broadcast address

55.110.255.255

Is 193.43.65.190 with 255.255.255.128 mask a valid host IP?

Yes (subnet range 128-255)

What protocol finds the IP address when MAC address is known?

RARP (Reverse ARP)

How many layers does the OSI model consist of?

7 layers

Valid host range for subnet 192.168.168.188/26?

192.168.168.129-190

Which protocol does ping use?

ICMP (Internet Control Message Protocol)

Command to delete configuration stored in NVRAM?

erase startup

Which class of IP address has the most host addresses by default?

Class A (16,777,214 hosts per network)

Which WLAN IEEE specification allows up to 54Mbps at 2.4 GHz?

802.11g (G)

What is PAT?

Port Address Translation - allows one IP to serve many users (NAT overload)

What is a stub network?

A network with only one exit point

Where is a hub specified in the OSI model?

Physical layer (Layer 1)

Command to backup IOS?

copy flash tftp