Network Fundamentals Flashcards
What is TCP port 20/21
FTP
What is TCP port 22
SSH
What is TCP port 23
Telnet
What is TCP port 25
SMTP
What is TCP port 53
DNS
What is TCP port 80
HTTP
What is TCP port 110
POP3
What is TCP port 443
HTTPS
What is the class A private address range
10.0.0.0 - 10.255.255.255
What is the class B private address range
127.16.0.0 - 127.31.255.255
What is the class C private address range
192.168.0.0 - 192.168.255.255
What is a unicast address
one to one
What is a broadcast address
one to all
What is a multicast address
one to many
What is an ipv6 anycast address
one to closest
What is an ipv6 link local address
Layer 2 domain, for communicating internally. Starts with FE80::/10
What is an ipv6 unique/site local address
Used in organisations, like private addresses. Begin with FC00::/7
What is an IPv6 global address
Used to access internet, start with 2000::/3
What are the 7 layers of OSI model
Application Presentation Session Transport Network Datalink Physical
What are the 4 layers of TCP/IP model
Application Transport Internet Network
At the Transport layer, data is broken in to TCP…
segments
At the Internet layer (TCP/IP) or Network later (OSI) , tcp segments are encapsulated as…
IP packets
At the Network layer (TCP/IP) or Data link (OSI), packets are encapsulated as…
Frames
What is bandwidth
The capacity of a medium to carry data
What is throughput
the measure of the transfer of bits across the media over a given period of time
What are the benefits of using copper cabling
Inexpensive Easy to install
What are the 3 main types of copper media
Unshielded Twisted Pair Shield Twisted Pair Coaxial
What is a physical topology
Describes the layout of the physical components
What is a logical topology
How the data flows through the network
What is a rollover cable
Connects to switch or router console port
What is a straight through cable
Connects dissimilar devices. Computer to switch etc
What is a crossover cable
Used for computer to computer or switch to switch, and computer to router (both are hosts)
What is UDP port 53
DNS
What is UDP port 67/68
DHCP
What is UDP 69
TFTP
What is UDP port 123
NTP
What is UDP port 161
SNMP
What protocols sit at layer 7
FTP Telnet TFTP SMTP SNMP DNS HTTP
What protocols sit at layer 6
Any presentation protocols e.g ASCII, jpg, .doc
What happens at layer 5
The establishment and teardown of sessions
What protocols sit at layer 4
TCP. UDP
What protocols and devices sit at layer 3
IP, routing and path determination, routers, ARP
What protocols and devices sit at later 2
Ethernet, frame relay, PPP, HDLC, MAC address, switches
What devices sit at layer 1
Bits transferred on media, hubs, repeaters, cables
Name the ipv4 class A range
1-126
Name the ipv4 class B range
128-191
Name the ipv4 class C range
192-223
How many bits are ipv4 address
32
How many bits are ipv6 address
128
What is the purpose of a subnet mask
to differentiate network bits from host bits
What is the purpose of the default gateway
To send packs off the local network
What is the range of ipv6 global unicast addresses
2000 - 3FFF
If an ipv6 address begins with FE80, what type is it
Link local
If an IPv6 address begins with FF00::/8 , what is it
Multicast
What are the 3 parts of a ipv6 global unicast address
Global routing prefix - 48 bits Subnet ID - 16 bits Interface ID - 64 bits
What is Stateless Address Autoconfiguration (SLAAC)
A method that allows a device to obtain its prefix, prefix length and default gateway address information from an IPv6 router without the use of a DHCPv6 server
How is ipv6 routing enabled
“ipv6 unicast-routing”
What is Neighbour discovery protocol (NDP)
Its how IPv6 determines layer 2 addresses (replacing ARP)
What is meant by Dual Stack
Allows IPv4 and IPv6 to coexist on the same network
In IPv6, what is meant by tunnelling
A method of transporting an IPv6 packet over an IPv4 network
What is the difference between a 3 tier and collapsed core architecture
3 tier includes an access, distribution and core layer. Collapsed core condenses core and distribution in one layer.
Name the UTP cable standards
Cat 3 - 10 Mbps Cat 4 - 20 Mbps Cat 5 - 100 Mbps Fast ethernet Cat 5e - 1000 Mbps Gigabit eth Cat 6 - 2500 Mbps
What kind of header is this
TCP
What kind of header is this
UDP
What type of header is this

IP header
In a TCP header, what is the source & destination port used for
source port - port number of application on host sending data
destination port - port number of application on the destination host
On a tcp header, what is the sequence number used for
Number used by TCP to put data back in correct order
What is a TCP acknowledgement number
The value is the tcp octect that is expected next
What is the TCP header length
indicates wheres the data begins
What is the TCP reserved field
Always set to 0
What are the TCP code bits/flags
Controls functions used to set up and terminate session
What is the tcp window field
The window size the send is willing to accept in octects
What is the tcp checksum field
Performs CRC check, used because TCP doesn’t trust the lower layers and checks everything. Checks header and data fields.
What is the TCP urgent field
Valid only if urgent pointer in the code bits is set. If so, value indicates offset from current sequence number in octets, where the segment of nonurgent data begins
What is the TCP options field
May be 0 meaning no options are set, or a multiple of 32
What is the TCP data field
Handed to lower layers, the data from upper layers.
In an IPv4 header, what does the version field do, for ipv4 this is 0100
Contains a 4 bit binary value identifying the IP packet version
In an IPv4 header, what does the field Differentiated Services do
used to determine the priority of each packet
formally called Type of service
In an IPv4 header, what does the TTL field do
is used to limit lifetime of a packet, commonly referred to as hop count
In an IPv4 header, what does the protocol field do
indicates the data payload type that the packet is carrying, which enables the network layer to pass the data to the appropriate upper layer protocol
In an IPv4 header, what does the Internet Header length field do
bit binary value identifying the number of 32 bit words in the header
In an IPv4 header, what does the total length field do
that defines the entire packet size including header and data, in bytes
In an IPv4 header, what does the Header Checksum field do
is used for error checking of the IP header
In an IPv4 header, what does the Identifcation field do
uniquely identifies the fragment of an original IP packet
In an IPv4 header, what does the Flags field do
identifies how the packet is fragmented
In an IPv4 header, what does the Fragment offset field do
- identifies the order in which to place the packet fragment in the reconstruction of the original unfragmented packet
What type of header is this.

IPv6
In an ipv6 header what does the Version field do
- 4 bit binary value identifying the IP packet version, for ipv6 this is 0110
In an ipv6 header what does the Traffic class field do
equivalent to the IPv4 DS field, used to classify packets
In an ipv6 header what does the flow label field do
provides a service for real time applications, used to inform routers and switches to maintain the same path for the packet flow so that packets are not reordered
In an ipv6 header what does the Payload Length field do
equivalent to the total length fields in IPv4 header, defines the entire packet size including header and optional extension
In an ipv6 header what does the Next Header field do
- equivalent to the IPv4 protocol field,
- Indicates the sate payload type that the packet is carrying enabling the network layer to pass the data to the appropriate upper later protocol.
In an ipv6 header what does the Hop Limit field do
replaces the IPv4 TTL field, Value is decremented by 1 by each routed that forwards the packet
In SLAAC, the how is the interface ID generated
Using MAC address, padded with FFFE, and the 7th bit in the MAC address gets flipped.
In NDP, what is the destination address of a router solicitation packet
FF02::2
In NDP, what is the destination address of a router advertisement packet
FF02::1
What is that scope of an IPv6 multicast address that starts with FF02
Local link
Which type of unicast address is automatically configured on all interfaces that are enabled for IPv6?
Link local