Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CompTIA Network + N10-008 > 1.4 Given a scenario, configure a subnet and use appropriate IP addressing schemes. > Flashcards

1.4 Given a scenario, configure a subnet and use appropriate IP addressing schemes. Flashcards

1
Q

Networking with IPv4

A
  • IP Address, e.g., 192.168.1.165
    – Every device needs a unique IP address
  • Subnet mask, e.g., 255.255.255.0
    – Used by the local device to determine what subnet it’s on
    – The subnet mask isn’t (usually) transmitted
    across the network
    – You’ll ask for the subnet mask all the time
    – What’s the subnet mask of this network?
  • Default gateway, e.g., 192.168.1.1
    – The router that allows you to communicate
    outside of your local subnet
    – The default gateway must be an
    IP address on the local subnet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Special IPv4 addresses

A
  • Loopback address
    – An address to yourself
    – Ranges from 127.0.0.1 through 127.255.255.254
    – An easy way to self-reference (ping 127.0.0.1)
  • Reserved addresses
    – Set aside for future use or testing
    – 240.0.0.1 through 254.255.255.254
  • Virtual IP addresses (VIP)
    – Not associated with a physical network adapter
    – Virtual machine, internal router address
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

DHCP

A
  • IPv4 address configuration used to be manual
    – IP address, subnet mask, gateway,
    DNS servers, NTP servers, etc.
  • Dynamic Host Configuration Protocol
    – Provides automatic addresses and
    IP configuration for almost all devices
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

APIPA - Automatic Private IP Addressing

A
  • A link-local address - No forwarding by routers
  • IETF has reserved
    169.254.0.1 - through 169.254.255.254
    – First and last 256 addresses are reserved
    – Functional block of
    169.254.1.0 through 169.254.254.255
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

NAT (Network Address Translation)

A
  • It is estimated that there are over 20 billion devices
    connected to the Internet (and growing)
    – IPv4 supports around 4.29 billion addresses
  • The address space for IPv4 is exhausted
    – There are no available addresses to assign
  • How does it all work?
    – Network Address Translation
  • This isn’t the only use of NAT
    – NAT is handy in many situations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

RFC 1918 Private IPv4 Addresses

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Static NAT

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

NAT Overload / Port Address Translation (PAT)

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Unicast

A
  • One station sending information to another station
  • Send information between two systems
  • Web surfing, file transfers
  • Does not scale optimally for streaming media
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Broadcast

A
  • Send information to everyone at once
  • One packet, received by everyone
  • Limited scope - the broadcast domain
  • Routing updates, ARP requests
  • Not used in IPv6 - focus on multicast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Multicast

A
  • Delivery of information to interested systems
    – One to many
  • Multimedia delivery, stock exchanges
  • Very specialized
    – Difficult to scale across large networks
  • Used in both IPv4 and IPv6
    – Extensive use in IPv6
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Anycast

A
  • Single destination IP address has
    multiple paths to two or more endpoints
    – One-to-one-of-many
    – Used in IPv4 and IPv6
  • Configure the same anycast address on different devices
    – Looks like any other unicast address
  • Packets sent to an anycast address are delivered to the closest interface
    – Announce the same route out of multiple data centers,
    clients use the data center closest to them
    – Anycast DNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Classful Subnetting

A
  • Very specific subnetting architecture
    – Not used since 1993
    – But still referenced in casual conversation
  • Used as a starting point when subnetting
    – Standard values
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The construction of a subnet

A
  • Network address
    – The first IP address of a subnet - Set all host bits to 0 (0 decimal)
  • First usable host address
    – One number higher than the network address
  • Network broadcast address
    – The last IP address of a subnet - Set all host bits to 1 (255 decimal)
  • Last usable host address
    One number lower than the broadcast address
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

VLSM (Variable Length Subnet Masks)

A
  • Class-based networks are inefficient
    – The subnet mask is based on the network class
  • Allow network administrators to define their own masks
    – Customize the subnet mask to specific network requirements
  • Use different subnet masks in the same classful network
    – 10.0.0.0/8 is the class A network - 10.0.1.0/24 and 10.0.8.0/26 would be VLSM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Four Important Addresses

A
  • Network address / subnet ID
    – The first address in the subnet
  • Broadcast address
    – The last address in the subnet
  • First available host address
    – One more than the network address
  • Last available host address
    – One less than the broadcast address
17
Q

Magic number subnetting

A
  • Very straightforward method
    – Can often perform the math
    in your head
  • Subnet with minimal math
    – Still some counting involved
  • Some charts might help
    – But may not be required
    – CIDR to Decimal
    – Host ranges
18
Q

The magic number process

A
  • Convert the subnet mask to decimal
  • Identify the “interesting octet”
  • Calculate the “magic number”
    – 256 minus the interesting octet
    – Calculate the host range
  • Identify the network address
    – First address in the range
  • Identify the broadcast address
    Last address in the range
19
Q

Seven second subnetting

A
  • Convert IP address and subnet mask to decimal
    – Use chart to convert between CIDR-block notation and decimal
    – Same chart also shows the number of devices per subnet
  • Determine network/subnet address
    – Second chart shows the
    starting subnet boundary
  • Determine broadcast address
    – Chart below shows the
    ending subnet boundary
  • Calculate first and last usable IP address
    – Add one from network address,
    subtract one from broadcast address
20
Q

IPv6 addresses

A
  • Internet Protocol v6 - 128-bit address
    – 340,282,366,920,938,463,463,374,607,431,768,211,456
    addresses (340 undecillion)
    – 6.8 billion people could have
    5,000,000,000,000,000,000,000,000,000 addresses each
21
Q

IPv6 address compression

A
  • Your DNS will become very important!
  • Groups of zeros can be abbreviated
    with a double colon ::
    – Only one of these abbreviations
    allowed per address
  • Leading zeros are optional
22
Q

Configuring IPv6 with a modified EUI-64

A
  • Static addressing can be useful
    – The IP address never changes
  • What other address never changes?
    – The MAC address
  • Extended Unique Identifier (64-bit)
  • Combined a 64-bit IPv6 prefix and the MAC address
    – Wait, the MAC address is only 48-bits long!
  • You’re going to need some extra bits
    – And a minor change to the MAC address
23
Q

Converting EUI-48 to EUI-64

A
  • Split the MAC
    – Two 3-byte (24 bit) halves
  • Put FFFE in the middle
    – The missing 16 bits
  • Invert the seventh bit
    – Changes the address from globally unique/universal
    – Turns the burned-in address (BIA) into a locally
    administered address
    – This is the U/L bit (universal/local)
24
Q

IPV6 Addressing: Shortcut for flipping the 7th bit

A
  • Quickly convert the MAC address - create a chart
  • Count from 0 to F in hex - two columns, groups of four
  • Quickly convert the second character of the first hex byte
    – Change it to the other value
25
Q

Assigning IPv6 Addresses

A
  • Internet Assigned Numbers Authority (IANA) provides address blocks to RIRs (Regional Internet Registries)
  • RIRs assigns smaller subnet blocks to ISPs (Internet Service Providers)
  • ISP assigns a /48 subnet to the customer
26
Q

Tunneling IPv6

A
  • 6 to4 addressing
    – Send IPv6 over an existing IPv4 network
    – Creates an IPv6 based on the IPv4 address
    – Requires relay routers
    – No support for NAT
  • 4in6 - Tunnel IPv4 traffic on an IPv6 network
27
Q

Teredo/Miredo

A
  • Tunnel IPv6 through NATed IPv4
    – End-to-end IPv6 through an IPv4 network
    – No special IPv6 router needed
    – Temporary use - We’ll have IPv6 native networks soon (?)
  • Miredo - Open-source Teredo for Linux,
  • BSD Unix, and Mac OS X - Full functionality
28
Q

Dual-stack routing

A
  • Dual-stack IPv4 and IPv6 - Run both at the same time
    – Interfaces will be assigned multiple address types
  • IPv4
    – Configured with IPv4 addresses
    – Maintains an IPv4 routing table
    – Uses IPv4 dynamic routing protocols
  • IPv6 - Configured with IPv6 addresses
    – Maintains a separate IPv6 routing table
    – Uses IPv6 dynamic routing protocols
29
Q

Howdy Neighbor

A
  • There’s no ARP in IPv6
    – So how do you find out the MAC address of a device?
  • Neighbor Solicitation (NS) -Sent as a multicast
  • Neighbor Advertisement (NA)
30
Q

NDP (Neighbor Discovery Protocol)

A
  • No broadcasts! - Operates using multicast over ICMPv6
  • Neighbor MAC Discovery - Replaces the IPv4 ARP
  • SLAAC (Stateless Address Autoconfiguration)
    – Automatically configure an IP address
    without a DHCP server
  • DAD (Duplicate Address Detection) - No duplicate IPs!
  • Discover routers
    – Router Solicitation (RS) and Router Advertisement (RA)

CompTIA Network + N10-008 (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions