1.3–1.7 – Routing, Wireless, &c. Flashcards

1
Q

What is: AS

A

Autonomous System

  • A group of IP routes under common control
  • A group of one or more IP prefixes, run by a network operator, which has a single and clearly defined routing policy.
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2
Q

What is: IGP

A

Interior Gateway Protocol

  • Used within a single AS.
  • Not intended as a route between autonomous systems.
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3
Q

What is: EGP

A

Exterior Gateway Protocol

  • Used to route between autonomous systems
  • The most common EGP is: BGP
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4
Q

What is: BGP

A

Border Gateway Protocol

  • The most common EGP.
  • A Hybrid routing protocol
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5
Q

What is: OSPF

A

Open Shortest Path First

  • An IGP.
  • A Link-state routing protocol.

• IPv4 dynamic routing uses
OSPFv2.

• IPv6 dynamic routing uses OSPFv3.

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6
Q

What is: RIP

A

Routing Information Procotol

  • An IGP.
  • A distance-vector routing protocol.
  • IPv4 dynamic routing uses RIPv2.
  • IPv6 dynamic routing uses RIPng (RIP next generation)
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7
Q

What is: EIGRP

A

Enhanced Interior Gateway Routing Protocol.

  • Proprietary to Cisco.
  • An IGP.
  • A distance-vector routing protocol.
  • IPv4 dynamic routing uses EIGRP.
  • IPv6 dynamic routing uses “EIGRP for IPv6”.
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8
Q

What is a distance-vector routing protocol?

A

A dynamic routing protocol that determines the best route based on the number of “hops.”

  • It will always take the route with the least number of hops.
  • Good for smaller networks. Does not scale well to larger networks.
  • Examples: RIP, EIGRP
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9
Q

What is a Link-state routing protocol?

A

A dynamic routing protocol that determines the best route based on the current connectivity and speed.

  • It will always take the fastest route.
  • Very scalable. Used most often in large networks.
  • Example: OSPF
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10
Q

What is a Hybrid-state routing protocol?

A

Combines the considerations of Link-state routing, distance-vector routing, and other factors, to determine the best route.

• Example: BGP

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11
Q

What is Dual-Stack Routing?

A

Running both IPv4 and IPv6 at the same time.

Each device is assigned an address for both type.

The protocols do not talk to each other, but devices can communicate on the network using either.

Routers will maintain separate routing tables for each.

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12
Q

What is NDP?

A

Neighbor Discovery Protocol

  • Network discovery used by IPv6.
  • Since IPv6 doesn’t use broadcast, this operates using multicast with ICMPv6.
  • Includes SLAAC, DAD, RS/RA, and NS/NA
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13
Q

What is RS and RA?

A

Router Solicitation and Router Advertisement

  • Used in IPv6 to discover routers on the network.
  • Routers will transfer IPv6 address info, prefix value, prefix length, etc.
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14
Q

What is NS and NA?

A

Neighbor Solicitation and Neighbor Advertisement

  • Used in IPv6 to discover the MAC address of other devices on the network, based on IPv6 address.
  • Also used to test for duplicate IPv6 addresses.
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15
Q

What is DAD?

A

Duplicate Address Detection

Used by IPv6.

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16
Q

What is SLAAC?

A

Stateless Address Autoconfiguration

Used by IPv6 instead of DHCP.

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17
Q

What is CoS?

A

Class of Service

A form of QoS that is performed at Layer 2 (by switches, usually applied in the intranet).

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18
Q

What is DiffServ?

A

Differentiated Services

A form of QoS that is performed at Layer 3, by routers.

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19
Q

What is PAT?

A

Port Address Translation

also known as NAT overload.

Part of the NAT process, ports are tracked and translated by the router to differentiate traffic between multiple internal device destinations.

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20
Q

What is NAT overload?

A

Also known as PAT.

Part of the NAT process, ports are tracked and translated by the router to differentiate traffic between multiple internal device destinations.

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21
Q

What is Destination NAT?

A

Another name for Port Forwarding.

An external IP and port number are mapped by a router to an internal IP and port.

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22
Q

What is Static NAT?

A

Another name for Port Forwarding.

An external IP and port number are mapped by a router to an internal IP and port.

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23
Q

What is an ACL?

A

Access Control List

The list of Access Rules within a firewall. Rules are configured for specifics, to either Allow or Deny.

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24
Q

What is the difference between Circuit Switching and Packet Switching?

A

Circuit Switching:
• Circuit is established between endpoints before any data passes
• That circuit cannot be shared, even when idle.
• Examples: POTS, T1, T3

Packet Switching:
• Data is grouped into packets
• The connection is usually shared
• One connection may have more bandwidth allocated to it than another
• Examples: DSL, Cable modem, satellite, wireless

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25
Q

What is the range of possible IPv4 loopback addresses?

A

127.0.0.1
through
127.255.255.254

Although, some operating systems will only recognize 127.0.0.1.

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26
Q

What is a Class E IP address, and what is the range of possible addresses?

A

Reserved IP addresses.

(Address that cannot be used, set aside for future use or testing)

First octet:
240 through 255

27
Q

What is the range of Class A IP addresses?

A

First octet:

1 through 126

28
Q

What is the range of Class B IP addresses?

A

First octet:

128 through 191

29
Q

What is the range of Class C IP addresses?

A

First octet:

192 through 223

30
Q

What is a Class D IP address, and what is the range of possible addresses?

A

Multicast

First octet:
224 through 239

31
Q

List all possible values for a subnet mask octet.

A
0
128
192
224
240
248
252
254
255
32
Q

What is a VLSM?

A

Variable Length Subnet Mask

A subnet that falls outside of the class-based categories.

This uses “classless” addressing.

33
Q

What is APIPA and how does it work?

A

Automatic Private IP Addressing

If a device does not find a DHCP server, it will randomly select an IP address in this range:

169.254.1.0 through 168.254.254.255

It performs an ARP request on the address it selects to confirm it is available, and assign it to itself.

This allows it to communicate with other devices on its network, but it will not be able to communicate through a router.

34
Q

What is an EUI-64?

A

Extended Unique Identifier 64-bit

A 64-bit value that, when combined with the 64-bit network prefix, is used to create an automatically self-assigned static IPv6 address which can be used to communicate worldwide.

35
Q

How is an EUI-64 created?

A

The device takes its MAC address and:

  • Inverts the 7th bit. (In Hex, this changes the second character/value.)
  • Adds these 16 bits to the middle: FFFE
36
Q

What ports does DHCPv6 use?

A

The server receives on udp/546

The client receives on udp/547

37
Q

To convert a MAC address to an EUI-64, what are the conversion used for the second hex character?

A

0: 2
1: 3
4: 6
5: 7
8: A
9: B

C:E

D:F

38
Q

What wireless topologies exist?

A

Infrastructure
• the most common
• all devices join and communicate through an access point

Ad hoc
• no access point or pre-existing infrastructure
• devices are configured to communicate directly to each other

Mesh
• Ad hoc devices discover each other and use each other to form a mesh cloud
• it self-forms and self-heals if a device is removed

39
Q

What is Z-Wave, how does it work, and what is it used for?

A

• A category of IoT technologies

• Primarily used in home automation networking
- example, control lights, locks, garage doors

• Uses wireless mesh networking
- Z-wave nodes can hop through other Z-wave nodes to get to their destination

• Uses the ISM (Industrial, Scientific, and Medical) band (900 MHz frequencies)
- So, there are no conflicts with 802.11 networks

40
Q

What is ANT and ANT+, how does it work, and what is it used for?

A
  • An IoT ultra-low-power protocol
  • Often used for fitness devices, heart rate monitors, etc.
  • Uses the 2.4 GHz ISM band, but a separate service and type of networking from 802.11 and Bluetooth
41
Q

What is RFID, how does it work, and what is it used for?

A

Radio-Frequency Identification

  • Used in access badges, pet identification, any type of inventory or anything that needs to be tracked
  • The RFID devices are usually not themselves powered. They get powered by the radio energy transmitted to the tag.
  • RF powers the tag, and an ID is transmitted back.
42
Q

What is 802.11a?

A
  • One of the two original wireless standards
  • Released 1999
  • 5 GHz
  • 20 MHz channel bandwidth
  • 54 Mbits/s throughput
  • single stream
  • Not commonly seen today
43
Q

How does 5 GHz compare with a 2.4 GHz?

A
  • 2.4 GHz will be roughly three times the range of 5 GHz.
  • This is because higher frequencies tend to be absorbed by objects in the way, rather than bouncing off them.
  • However, 2.4 GHz frequencies will tend to allow for less throughput.
  • And, 2.4 GHz has more frequency conflicts, as it is commonly used by other devices such as Bluetooth, microwaves, baby monitors, cordless phones, etc.
44
Q

What is 802.11b?

A
  • One of the two original wireless standards
  • Released 1999
  • 2.4 GHz
  • 22 MHz channel bandwidth
  • single stream
  • 11 Mbit/s throughput
45
Q

What is 802.11g?

A
  • Released 2003
  • Essentially an upgrade to 802.11b
  • Backwards compatible with 802.11b, so an 802.11g WAP could work with 802.11b clients.
  • 2.4 GHz (same as 802.11b)
  • 20 MHz channel bandwidth (same as 802.11a)
  • 54 Mbit/s throughput (about the same as 802.11a)
46
Q

What is 802.11n?

A
  • Released 2009
  • An upgrade to 802.11 a, b, and g
  • Operates at both 5 and/or 2.4 GHz
  • Larger channel bandwidths, allowing either 20 or 40 MHz
  • First to use MIMO
  • Max of 4 MIMO streams
  • 600 Mbit/s (using multiple streams of data simultaneously)
47
Q

What is MIMO?

A

Multiple Input Multiple Output

The wireless technology to use multiple radios and antennas to transmit multiple streams of data simultaneously on the same frequency.

802.11n was the first wireless standard to utilize it.

48
Q

What is 802.11ac?

A
  • Released 2014
  • Improved on 802.11n
  • 5 GHz exclusively
  • Larger channel bandwidths, allowing 40, 80, or 160 MHz
  • Denser signaling modulation for faster data transfers
  • Max of 8 MU-MIMO streams
  • About 6.8 Gbit/s throughput
49
Q

What is MU-MIMO?

A

Multi-User Multiple Input Multiple Output

Same as MIMO, but allows data to be sent on the same frequency to multiple/different clients at the same time

50
Q

What is GSM?

A

Global System for Mobile Communications

  • A 2G cellular network
  • Designed for voice-only
  • Originally used circuit-switching
  • Received some minor upgrades for some packet-switching to allow for data
  • Used by AT&T and T-Mobile
51
Q

What is CDMA?

A

Code Division Multiple Access

  • A 2G cellular network
  • Designed for voice-only
  • Originally used circuit-switching
  • Received some minor upgrades for some packet-switching to allow for data
  • Used by Verizon and Sprint
52
Q

What is TDMA?

A

Time-Division Multiple Accsss

  • Used by GSM networks
  • Multiple streams are combined into a single stream, and then broken out again.
53
Q

What is 4G LTE?

A

4th Generation / Long Term Evolution

  • Based on GSM and Edge
  • Converged standard, now used by all providers
  • Originally supported download rates of 150 Mb/s.
  • Now with LTE-A (Advanced) supports up to 300 Mb/s
54
Q

What is EDGE?

A

Enhanced Data Rates for GSM Evolution

55
Q

What is CASB?

A

Cloud Access Security Broker

Manages security for cloud access.

56
Q

What is an IP Helper?

A

Another name for DHCP Relay

57
Q

What is DHCP Relay?

A

Configured in a router, so that when it receives a broadcast for DHCP, it converts it to a unicast to the DHCP server’s IP address (pre-configured in the router) and forwards it on.

It then converts the unicast response back into a broadcast and forwards it to the source network.

58
Q

What is an ASN?

A

Autonomous System Number

Routing prefixes, which are assigned in blocks by IANA and distributed by the Regional Internet Registry (RIR).

ASNs are used to control routing with BGP routing protocols to route traffic across the network.

59
Q

What is LWAPP?

A

Lightweight Access Point Protocol

A protocol that can control multiple wireless access points at once, from a single point.

This can reduce the amount of time spent on configuring, monitoring or troubleshooting a large network.

60
Q

What is a Routing Protocol?

A

Routers exchange routing topology information with each other by using a routing protocol.

61
Q

In routing, what is “convergence”?

A

Convergence is when all routers in a network learn the route to all connected networks.

  • Routers exchange routing topology information with each other by using a routing protocol.
  • When all routers have exchanged routing information with all other routers within a network, the routers are said to have converged.
  • In other words: In a converged network, all routers “agree” on what the network topology looks like.
62
Q

What is HSRP?

A

Hot Standby Router Protocol

A proprietary Cisco protocol.

Uses a virtual IP and MAC address to provide an active router and a standby router.

If the Active Router goes offline, the Standby Router will take over.

63
Q

What is a Piconet?

A

Personal Area Network (PAN) over Bluetooth is known as piconet.