Intro Flashcards
Peer to peer network characteristics
Lacks centralised administration
Easy to create
Less cost to implement
Intermediary devices
Connect individual hosts to the network
Direct the path of data
Connection options that provide always-on, high-bandwidth internet connection to computers in a home office
Cable
DSL
Functions provided to users by context-sensitive help feature of Cisco, IOS CLI
Displaying a list of all available commands in current mode.
Determining which option, keyword, or argument is available for the entered command.
Which two host names follow the guidelines for naming conventions on Cisco IOS devices
SW Branch 799
RM-3 Switch-2A4
How dose the (service password-encryption) enhance password security on Cisco routers and switches
Ot encryptions the passwords that are stored in router or switch configuration files
What’s are the 2 characteristics of RAM on a Cisco device
The contents of the RAM are lost during a power cycle.
The configuration that is actively running on the device is stored in the RAM
IOS modes
Int config mode Priv exe mode Line config mode Global config mode User exe mode
Client to webserver
Order of the protocol stack
HTTP
TCP
IP
Ethernet
3 application layer protocols are park of the TCP/IP protocol suite
DHCP
DNS
FTP
What are the proprietary protocols
Protocols developed by organisations who have control over there definition and operation
Which 3 layers of the OSI model are comparable in function to the application layer of the TCP/IP model
Application
Presentation
Session
At which layer of the OSI model would a logical address be encapsulated
Network layer
Which PDU (Protocol Data And Unit) format is used when bits are revived from network medium by the NIC of a host
Frame
Which characteristics describes the default gateway of a host computer
The logical address of the router interface on the same network as the host computer
ISOC
Promotes the open development evolution and use of the internet throughout the world
ISO
Largest developer of international standards in the world for a wide variety of products and services, known for OSI model
IANA
Responsible for the overseeing and managing of IP addresses, domain name management and protocol identifiers
Throughput
Measure of bits transferred across the media over a given period of time
What interference would electrical cables and fluorescent lights have on CAT cabling
EMI
RFI
Data link layer provides
Accepts layer 3 packets and encapsulates them into frames.
Provides media access control and provides error detection:
What is true concerning physical and logical topologies
Logical topologies refer to how a network transfers data between devices
Star topology
End devices connect to a central intermediate device, which in turn connects to other central intermediate devices
What is contained in the trailer of a data link frame
Error detection
What is the function of the CRC value that is found in the FCS field of a frame
To verify the integrity of the revived frame
Data link sub layer that identifies the network layer protocol encapsulated in the frame
LCC logical link control
Combination of point to point, HUB, spoke and mesh topology
Hybrid
Ethernet frame sizes
MAX
MIN
1518
64
Ethernet
Defines the most common type of LAN in the world.
Function and features of logical link control sub layer in Ethernet standards
LLC is implemented in the software.
The data link layer uses LLC to communicate with the upper layers of the protocol suite.
MAC addresses
Must be globally unique
Destination addresses used in ARP request frame
FFFF.FFFF.FFFF
When a device is sending data to another device on a remote network, the Ethernet frame is sent to the MAC address of the default gateway
True
The potential network problems that can result from ARP operation
Network attackers could manipulate MAC addresses and IP addresses mappings in ARP messages with the intent of intercepting network traffic.
On large networks with a low bandwidth, multiple ARP broadcasts could cause data communication delays.
Collision fragment
Runt frame
On a Cisco switch,
WHAT?
memory buffering is used to buffer frames in queues linked to specific incoming and outgoing ports
Port-based
ARP
WHAT?
is a technique that is used to send fake ARP messages to the other hosts in the LAN. The aim is to associate IP addresses to the wrong MAC addresses
Spoofing
ARP poisoning
Which statement is true about MAC addresses
The first three bytes are used by the vendor assigned OUI (Organisationally Unique Identifier)
2 characteristics of IP
Operates independently of the network media.
Dose not require a dedicated end to end connection.
When a connectionless protocol is in use of l lower layer of the OSI model, how is missing data detected and retransmitted
Upper layer connection-oriented protocols keep track of the data received and can request retransmission from the upper-level protocols on the sending host.
Whatcha field in the IPv4 header is used to prevent a packet from transversing a network endlessly
Time-To-Live
What IPv4 header field identifies the upper layer protocol carried in the packet
Protocol
What is one advantage that the IPv6 simplified header offers over IPv4
Efficient packet handling
What type of route is indicated by the code C in an IPv4 routing table on a Cisco router
Directly connected route
What routing table entry has a next hop address associated with a destination network
Remote routes
Following default settings what is the next step in the router boot sequence after the los IOS loads from
Locate and load the startup config file from NVRAM
2 types of router interfaces
WAN
LAN
Which 2 pieces of information are in RAM of a Cisco router during normal operation
Cisco IOS.
IP Routing Table.
What is the purpose of the startup configuration file on a Cisco router
To contain the commands that are used to initially configure a router on startup.
Which 3 commands are used to set up secure access to a router through a connection to the console interface
Login
Password Cisco
Line console 0
Which characteristics describes an IPv6 enhancement over IPv4
The IPv6 header is simpler than the IPv4 header is, which improves packet handling
How many bits in IPv4 address
32
Which 2 parts are components of an IPv4 address
Network portion
Host portion
What is the purpose of a subnet mask
To determine the subnet to which the host belongs
A message sent to all hosts on a remote network
Directed broadcast
What are the 3 characteristics of a multicast transmission
A single packet can be traced to a group of hosts.
Multicast transmissions can be used by routers to exchange routing information.
The range 244.0.0.0 to 244.0.0.255 is reserved to reach multicast groups on a local network.
Which 2 IPv4 to IPv6 transition techniques manage the interconnection of IPv6 domains
Dual stack
Tunnelling
Abbreviate 3FFE:1044:0000:00ab:0000:0000:0057
3FFE:1044:0:0:AB::57
2 types of IPv6 unicast addresses
Loop back
Link local
What are the 3 parts of an IPv6 global unicast address
A global routing prefix that is used to identify the network portion of the address provided by a ISP.
An interface ID that is used to identify networks inside of the local enterprise site.
A subnet ID that is used to identify networks inside of the local enterprise site.
Which protocol supports stateless address auto configuration (SLAAC) for the dynamic assignment of IPv6 addresses to a host
ICMPv6
What is the purpose of ICMP messages
To provide feedback of IP packet transmissions
What is indicated by a successful ping to the ::1 IPv6 address
Up is properly installed on the host
What field context is used by the ICMPv6 to determine that a packet has expired
Hop limit field
- 254.1.5
- 0.2.123
- 2.6.255
- 19.20.5
- 0.0.1
Link local Test net Experimental Private Loopback
A user is using traceroot, at which point would a router stop forwarding the packet
When the value in the TTL field reaches Zero
What is the result of connecting 2 or more switches together
The size of the broadcast domain is increased
What are the 2 reasons network administrators nights want to create subnets
Imported network performance.
Easier to implement security policies.
If a network device has a mask of
/28, how many IP addresses are available for hosts on the network
14
How many bits must be borrowed from the host portion of an address to accommodate a router with 5 connected networks
3
Last address (Broadcast)
(Net + Inc) -2
Increment
256-Mask
Host range
2 power of bits
/29 .248
11111000
E.g. 5 SN = 2 to the 5 = 32
3 host bits = 2 to the 3 = 8 -2(BC&NetID) =6
IPv6
Global Unicast
Multicast
Link Local
Loopback Address
2&3001
FF
FE80
::1
Router boot up
POST
Bootstrap loader
Load IOS
Config
Port requested from IANA in order to be used with a specific application.
Registered
Well known ports
0-1023
Which factor determines TCP window size
Amount of data the destination can process at one time
TCP session acknowledgement number represents
The next byte the destination expects to receive
What information is used by TCP to reassemble and reorder received segments
Sequence numbers
What dose TCP do if the sending source detects network congestion on the path to the destination
The source will decrease the amount of data it sends before it must receive acknowledgements from the destination
3 application layers using TCP
SMTP
FTP
HTTP
Well known port numbers registered Port numbers
HTTP Protocol standard
0-1023
1024-49151
80
Associated application layer protocol
Telnet
DNS
TCP/IP model layer used for formatting, compression and encryption
Application
Characteristics of the application layer of the TCP/IP model
Closest to end user
The creation and maintenance of dialogue between source and destination applications
SNMP
Simple Network Management Protocol
Peer to peer
Data exchange between 2 devices without a server
What do client/server and peer to peer network models have in common
Both models support devices in server and client roles
IMAP
Messages are kept in servers until detected from client machine
GET, PUT, POST
HTTP
DHCP discover message
The message comes from a client seeking a IP address.
All hosts receive the message, but only a DHCP server replys
Top level DNS domain
.com
SMBP Simple Message Block Protocol
Clients establish a long term connection to servers
Application layer protocol used to provide file share and print services to Microsoft applications
SMB
GET message
HTTP request from client to server
Firewall feature used to insure legitimate packets
State full packet inspection
Pre SSH steps
Give router host and domain name.
Generate set of secret keys for encryption.
CDP on Cisco device
CDP can be displayed globally or on a specific interface
Arp-d command
ARP cache is cleared
-6
Forces trace root to use IPv6
Display log messages on remotely connected sessions using telnet or SSH
Terminal Monitor
4 types of Network Attack
Reconnaissance
Access
DoS
Malicious Coda
Access attacks
Password Trust exploration Port exploration Port redirection Man in the middle
Mitigating Network Attacks
Device hardening-Remove software not in use.
Antivirus
Personal firewalls
Operating system patches
Private Addresses
- 0.0.0/8
- 16-31.0.0/16
- 168.0-255
ICMP
Internet Control Message Protocol
SVI
Switched Virtual Interface - Virtual LAN
Secure access to 3rd party’s
Extranet
Service password-encryption
Prevents a look over the shoulder on running config
PDU
Protocol Data Unit
Packet
Wireless
Radio Wave
CSMA/CD
Carrier-Sense Multiple Access
Collision Detection
ROM
Bootstrap.
Basic Diagnostic Software.
Limited IOS (Internetwork Operating System)
RAM - Volatile
Running config.
IP routing table.
MAC mappings in ARP cache.
NVRAM
Start up config
Transport Layer
3services
Flow control.
Connection Establishment.
Error Recovery.
DHCP
Default gateway address.
Subnet mask.
Shell
Closet to the user
Between user and Kernel
Kernel
Part of the OS.
TCP
Transport Control Protocol
