Network Stuff Flashcards
1
Q
What 2 ports are used by FTP? (File Transfer Protocol)
A
TCP Ports 20, and 21
2
Q
What port is used for Telnet?
A
TCP Port 23
3
Q
What port is used for SMTP? (Simple Mail Transfer Protocol)
A
TCP Port 25
4
Q
What port is used for TFTP? (Trivial File Transfer Protocol)
A
UDP Port 69
5
Q
What port is used for HTTP(Hyper Text Transport Protocol)?
A
TCP Port 80
6
Q
What port is used for POP3(Post Office Protocol)?
A
TCP Port 110
7
Q
What port is used for HTTPS?
A
TCP 443
8
Q
What does RAS stand for?
A
Remote Access Server
9
Q
What does L2TP stand for?
A
Layer 2 Tunneling Protocol
10
Q
What does PPTP stand for?
A
Point-to-Point Tunneling Protocol
11
Q
What does SSTP stand for?
A
Secure Sockets Tunneling Protocol
12
Q
What does RAID stand for?
A
Redundant Array of Independent Disks
13
Q
The following describes what level of RAID? 1) Also known as disk striping. 2) Requires at least 2 hard disks. 3) Primarily implemented to increase speed. 4) No fault tolerance 5) Utilizes 100% of space from all hard disks
A
RAID 0
14
Q
The following describes what level of RAID? 1) Also known as disk mirroring by providing an exact copy of another hard disk. 2) Implemented with exactly 2 hard disks. 3) High availability of data, extremely fault tolerant. 4) Slower performance since data has to be written twice. 5) Utilizes 50% of total disk space from both hard disks.
A
RAID 1
15
Q
The following describes what level of RAID? 1) Uses striping and has one disk dedicated to creating parity. 2) Requires at least 3 hard disks to implement. 3) Each hard disk should be the same capacity. 4) Used for a combination of fault tolerance and speed. 5) Calculating parity will slow down the performance slightly due to CPU usage. 6) The amount of space available is determined by the formula 1 -1/n (where n is the # of hard disks)
A
RAID 3
16
Q
The following describes what level of RAID? 1) The same as RAID 3 except parity is striped with the data
A
RAID 5
17
Q
The following describes what level of RAID? 1) Requires at least 4 hard disks to implement. 2) Uses striping and creates 2 parity stripes that are striped with the data. 3) Extremely high fault tolerance since 2 disks could fail and still have recoverable data. 4) Requires a complex controller to implement. 5) The amount of space available is calculated by 1-2/n
A
RAID 6
18
Q
The following describes what level of RAID? 1) Also known as mirroring and striping. 2) Requires at least 4 hard disks and must be an even # of hard disks. 3) Extremely fault tolerant allowing multiple hard disk failures. 4) Amount of space available is 50% of total space from all hard drives.
A
RAID 10
19
Q
The following describes what level of RAID? 1) Also known as RAID 5+0 and combines striping and RAID 5. 2) Requires at least 6 hard disks to implement. 3) Extremely fault tolerant while still maintaining high performance and data transfer rates. 4) Total available space is calculated by 1-1/n (where n is the # of disks used in each RAID 5 implementation
A
RAID 50
20
Q
What does SCSI stand for?
A
Small Computer System Interface
21
Q
What does SAS stand for?
A
Serial Attached SCSI
22
Q
What are the 4 components in a SAS system?
A
1) Initiator 2) Target 3) Service Delivery Subsystem 4) Expanders
23
Q
What does SATA stand for?
A
Serial Advanced Technology Attachment
24
Q
What does SAS stand for?
A
Serial Attached SCSI
25
What are the 4 components in a SAS system?
1) Initiator 2) Target 3) Service Delivery Subsystem 4) Expanders
26
What does SATA stand for?
Serial Advanced Technology Attachment
27
Name the 3 types of backups?
1) Full 2) Incremental 3) Differential
28
What port is used for NTP? (Network Time Protocol)
UDP Port 123
29
What port is used for IMAP? (Internet Message Access Protocol)
TCP Port 143
30
What does VTP stand for?
VLAN Trunking Protocol
31
Do the ends of a SCSI bus need termination?
Yes
32
What interface has 8 bit width - clock speed = 5Mhz and Bandwidth = 5 MBps?
SCSI
33
What interface has 8 bit width - clock speed = 10Mhz and Bandwidth = 10MBps?
Fast SCSI
34
What interface has 16 bit width - clock speed = 10Mhz and Bandwidth = 20MBps?
Fast Wide SCSI
35
What interface has 8 bit width - clock speed = 20Mhz and Bandwidth = 20MBps?
Ultra SCSI
36
What interface has 16 bit width - clock speed = 20Mhz and Bandwidth = 40MBps?
Ultra Wide SCSI
37
What interface has 8 bit width - clock speed = 40Mhz and Bandwidth = 40MBps?
Ultra2 SCSI
38
What interface has 16 bit width - clock speed = 40Mhz and Bandwidth = 80MBps?
Ultra2 Wide SCSI
39
What interface has 16 bit width - clock speed = 80Mhz and Bandwidth = 160MBps?
Ultra 3 SCSI
40
What interface has 16 bit width - clock speed = 160Mhz and Bandwidth = 320MBps?
Ultra 320 SCSI
41
What does LUN stand for?
Logical Unit Numbers
42
What interfaces are LUN's used by?
SCSI, iSCSI, and Fibre Channel to identify a logical unit on a bus
43
What are two other ways to indentify a LUN?
SCSI Device ID, and Disk serial numbers
44
What two interfaces do not need a unique ID or termination, and are full duplex switched serial point to point connections?
SAS, and SATA
45
What is the main difference between SAS, and SATA?
The power and data connectors are separated in SATA and one piece for SAS. You can connect a SAS to a SATA drive, but not vice versa
46
What port does DNS (Domain Name Service) utilize?
DNS utilizes TCP port 53 and UDP port 53
47
What port does NNTP (Network News Transfer Protocol) utilize?
NNTP utilizes TCP port 119
48
What port does SNMP (Simple Network Management Protocol) utilize?
SNMP utilizes UDP port 161
49
What port/s does DHCP (Dynamic Host Configuration Protocol) utilize?
DHCP utilizes UDP ports 67 and 68
50
When referring to the OSI model, the term "data" would refer to what layer/s?
Application, Presentation, and Session - The top 3 layers in that order.
51
When referring to the OSI model, the term "segment", would refer to what layer/s?
Transport layer
52
When referring to the OSI model, the term "packet", would refer to what layer/s?
Network layer
53
When referring to the OSI model, the term "frame" would refer to what layer/s?
Data Link layer
54
When referring to the OSI model, the term "bit" would refer to what layer/s?
Physical layer
55
Name the layers of the OSI model
Application, Presentation, Session, Transport, Network, Data Link, and Physical.
56
The following protocols and services run at which layer of the OSI model:
- Email protocols SMTP and POP3
- Telnet
- HTTP
- File Transfer Protocol (FTP)
- Simple Network Management Protocol (SNMP)
- Authentication (Anything dealing with user input)
Layer 7 aka The Application layer
57
What layer of the OSI model would the following full under:
- Compatibility with the operating system
- Proper encapsulation of data for network transmission
- Data formatting
- Data encryption, compression, and translation
Layer 6...aka The Presentation Layer
58
This OSI layer handles the creation, maintenance, and teardown of communications two hosts
Layer 5....aka The Session Layer
59
The OSI layer responsible for establishing logical end-to-end connections between systems. Making sure the segments get to their destination in the correct order and free of errors using either TCP or UDP protocol's.
Layer 4...aka The Transport Layer
60
IP runs at this layer of the OSI. Often referred to as "the routing layer"
Layer 3...aka The Network Layer
61
Basic switches operate at this layer of the OSI? MAC addresses are also utilized at this level, and error detection, but "Not" error recovery. The following terms are associated at this level as well:
- Ethernet
- High Data Link Control (HDLC)
- Point-to-Point Protocol(PPP)
- Frame Relay
Layer 2...aka The Data Link Layer
62
What are the 4 layers of the TCP/IP model?
Application, Transport, Internet (Internetwork), and Network Access
63
The OSI model layers of Application, Presentation, and Session, refer to what layer of the TCP/IP model?
Application layer
64
What is the process called when a sender waits for a positive message from the recipient that data was received, and if that message isn't received, the data is retransmitted?
Positive Acknowledgement with Retransmission (PAR)
65
What are the only 3 values TCP and UDP headers have in common?
Source port, Destination port, and Checksum
66
What does the term "socket" refer to?
The combination of IP address and port number
67
SSH (Secure Shell) utilizes what port?
TCP port 22
68
What port does SSL (Secure Socket Layer) utilize?
TCP port 443
69
The entire range of UDP ports from 16384 - 32767 are reserved for what type of traffic?
Voice
70
Fast Ethernet is defined by what IEEE standard? Also what is the maximum capacity?
IEEE 802.3U, and the maximum capacity is 100MBPS
71
Gigabit Ethernet is defined by what IEEE standard? Also what is the maximum capacity?
IEEE 802.3z and 802.3ab. Also the maximum capacity is 1000MBPS
72
What is the broadcast MAC address?
FF-FF-FF-FF-FF-FF
73
What does the 1st half of a multicast MAC address always start with?
The 1st half is always 0100.5e. The 2nd half will be in the range of 00-00-00 through 7F-FF-FF.
74
A Cisco switch will do one of the three things with an incoming frame?
Forward it, Flood it, or Filter it
75
What is the 1st thing a Cisco switch is going to look at with an incoming frame before deciding what to do with that frame.
It is going to look at the source MAC address 1st, and then use that address to dynamically build the MAC address table.
76
In the world of Cisco switching, what is the term used when describing what a switch does when it receives an unknown unicast frame
It floods the switch.
77
What does a Cisco switch do with an incoming frame that's determined to have the source port identical to the destination port.
The switch will filter (drop) the frame. *** Switches never send a frame back out the same port it came on ***
78
When a switch does have have an entry for an incoming frames destination MAC address, what term is used to describe what it does with that frame.
The switch will forward it.
79
What are the 3 processing methods a switch would used when forwarding a frame?
Store-and-forward (Stores entire frame and checks it for errors in its entirety), cut-through (No error checking), fragment-free (checks the 1st 64 bytes for errors)
80
What are the three layers of the Cisco switching model?
Access, Distribution, and Core
81
What is the protocol used in switching that determines a loop free path for frames, and ports that are not on that path will be placed into blocking mode?
STP (Spanning Tree Protocol) - STP, which is enabled on switches by default, uses the port speeds along a path to determine the overall cost and the best paths
82
What are 3 things that can be done on a switch as a basic security measure?
1) Close unused ports with the shutdown command
2) Prevent the port from trunking with the switchport mode access command
3) Place the port into a unused VLAN
83
What are 3 types of port security violation modes?
Protect, Restrict, Shutdown
84
Going from highest to lowest, double the number 1 7 times.
128 64 32 16 8 4 2 1
85
What is the class A address range, class B, class C, class D, and class E
```
Class A address range is 1 - 126
Class B address range is 128 - 191
Class C address range is 192 - 223
Class D address range is 224 - 239 **Reserved for multicasting**
Class E address range is 240 - 255
```
86
Ad Hoc WLAN's (Wireless devices communicating with no WAP involved) are also called what?
Ad hoc networks are also called iBSS or IBSS (Independent Basic Service Sets)
87
Name the two common kinds of infrastructure WLAN's.
BSS (Basic Service Set) - utilizes a single access point
| ESS's (Extended Service Set) - utilizes multiple AP's
88
Name the 4 common types of 802.11x wireless standards and be familiar with their operating frequencies and max speeds
1) 802.11a - 25 MBPS typical - Max 54 MBPS - 5 GHz
2) 802.11b - 6.5 MBPS typical - Max 11 MBPS - 2.4 GHz
3) 802.11g - 25 MBPS typical - Max 54 MBPS - 2.4 Ghz
4 802.11n - 200 MBPS typical - Max 540 MBPS - 2.4 Ghz and 5 GHz *** Also increases indoor range to 160 feet ***
89
What are 3 types of wireless Spread Spectrum methods?
1) FHSS - Frequency Hopping Spread Spectrum - Sender and receiver agree on a range to use - Bluetooth
2) DSSS - Direct Sequence Spread Spectrum - Spreads signal over entire range of frequencies at once - .11b, .11g, .11n
3) OFDM - Orthogonal Frequency Division Multiplexing - Splits the signal and sends fragments over different frequencies at the same time - .11a
90
What is CSMA/CD and CSMA/CA.
CSMA/CD is Carrier Sense Multiple Access Collision Detection
*** Used with Ethernet Networks***
CSMA/CA is Carrier Sense Multiple Access Collision Avoidance
*** Used with Wireless Networks ***
91
What are the 3 types of wireless security standards?
WEP - Wired Equivalent Privacy - least secure
WAP - Wi-Fi Protected Access - More secure
WAP2 - Most secure
92
What are the two forms of authentication WEP supports?
The two forms of authentication the WEP supports are:
Open and Shared key - Shared key considered to be less secure because of the "clear text challenge" the AP sends to the host.
** Also WEP uses One way authentication **
93
What protocol does WPA2 implement that allows is to be considered "fully secure"?
Through the use of CCMP (Counter Mode with Cipher Block Chaining Message Authentication Code Protocol) WPA2 is considered to be "fully secure"
94
What are the 3 vital functions that VPN's (Virtual Private Networks) offer?
1) Data origin Authentication - allows receiver to guarantee source of the packet
2) Encryption
3) Integrity - receiver's ability to ensure that the data was not affected or altered in any fashion as it traveled across the VPN
95
What are the 3 different protocols that can be used to create VPN's?
1) GRE (Generic Routing Encapsulation) - No encryption scheme
2) L2TP (Layer 2 Tunneling Protocol) - Hybrid of PPTP and Cisco's L2F - Also no encryption scheme
3) IPSec (IP Security) - Encryption and Authentication
96
What layer of the OSI does L2TP operate?
How about SSH(Secure Shell)?
S/MIME(Secure/Multipurpose Internet Mail Extensions)?
SSL(Secure Socket Layer)?
L2TP operates at layer 2 (Data Link layer) of the OSI model
SSH and S/MIME operate at layer 5 (Application layer)
SSL operates at layer 4 (Transport layer) ** Some documentation may have it running at layer 7 (presentation layer) **
97
What are 2 general types of remote access VPN's?
1) Client initiated - Remote user will use a VPN client to create a secure tunnel across a ISP's network.
2) Network Access Server Initiated - Misleading because still initiated by the client, but is started by accessing a NAS, and the NAS will then create the tunnel.
98
What is the size of the key used to encrypt data with DES?
DES uses a 56 bit key to encrypt data, thus making it very vulnerable
*** Triple DES aka TDES, aka 3TDES...avoid using 3DES. is used to increase the size of the key to 112 bits (effective security) ***
99
What encryption standard is being widely adopted around the world and can be run on any Cisco router that has IPSEC DES/TDES capability
AES (Advanced Encryption Standard)
100
What are the two encryption schemes?
1) Symmetric - aka Secret Key Encryption - Same key used for both encryption and decryption - Variations include stream algorithms
2) Asymmetric - Two keys for both sender and receiver - This PKE involves a public and private key for each user and before starting the encryption process the public key should be verified by a 3rd party called a CA(Certificate of Authority)
101
Name a very well known PKE (Public Key Encryption) scheme
RSA (Ron Rivest, Adi Shamir, and Len Adelman) is a well known PKE scheme
102
What algorithm allows the exchange of secret keys over a non-secure communications channel?
The Diffie-Hellman algorithm aka Exponential key agreement was developed in 1976 but still used today around the world.
103
IPSec is a combination of what 3 protocols?
1) Authentication Header (AH) - defines a method for authentication and securing data
2) Encapsulating Security Payload (ESP) - defines a method for authenticating, securing, and encrypting data
3) Internet Key Exchange (IKE) - negotiates the security parameters and authentication keys
104
AH (Authentication Header) Offers 3 things:
1) Data origin authentication
2) Data integrity
3) Anti-replay protection (optional)
What is the one thing it does not have? What does offer it?
The one thing AH does not offer is Data confidentiality. ESP (Encapsulating Security Payload) does.
105
What are the two modes AH and ESP can be run in?
1) Tunnel Mode - Entire IPSec process is transparent to the end hosts and uses specialized IPSec gateway devices to handle the workload.
2) Transport Mode - End hosts themselves perform the encapsulation meaning IPSec has to be running on both hosts. No new IP header is attached using transport mode
106
What does STP stand for? What is the purpose of it?
STP - Spanning Tree Protocol - Is set by default in switches to prevent switching loops....FYI - Does not have anything to do with routing loops.
107
What is the order of STP port states as a port goes from blocking to forwarding?
Blocking - Frames are not forwarded, but BPDUs are accepted
Listening - Frames are not forwarded, and the MAC address table is not yet being built
Learning - Frames are not forwarded. MAC addresses are being learned and the MAC address table is being built
Forwarding - Frames are forwarded, MAC addresses are still learned
108
In some material there is a fifth state in the order of STP going from blocking to forwarding, what is that state?
The 5th state is disabled - Port is disabled and cannot accept BPDUs
109
Given 2 switches connected via a crossover cable, when STP converges, of the 4 ports, how many will be blocked?
Only 1 port will be blocked once STP converges.
110
What are the terms and values for the Hello BPDU's used by all bridges in identifying situations when the STP algorithm needs to be run again?
Hello Time - Time between Hello BPDUs - Default - 2 sec
Max Age - The bridge should wait this amount of time after not hearing a Hello BPDU before attempting to change the STP topology - Default - 20 sec
Forward Delay - The amount of time a port should stay in the listening and learning stages as it changes from blocking to forwarding mode - Default - 15 sec
111
What is Portfast? and when should it be used?
Portfast allows a port to go from blocking to forwarding immediately - **** Should only be used on ports that are connected to an end user device (PC), not to other networking devices ****
112
What is trunking?
Trunking is the process of allowing VLAN traffic to flow over physically connected switches
113
What is ISL?
ISL is Inter-Switch Protocol which is a Cisco proprietary trunking protocol. *note* Only used between Cisco switches where the entire frame is encapsulated before transmission across the trunk
114
What is IEEE 802.1Q?
IEEE 802.1Q - Aka - "dot1q" is the industry standard trunking protocol...(Used with non-Cisco switches)
Dot1q does not encapsulate the entire frame, rather it places a 4-byte header on the Ethernet header indicating the desired VLAN
115
What has more overhead? ISL or Dot1Q?
ISL has significantly more overhead because it encapsulates every single frame. In contrast Dot1Q does not even place the 4-byte header on the native VLAN.
116
What are the five configuration modes options for trunk ports?
On - Trunk unconditionally
Off - Setting port to be an access port
Auto - Dynamic trunking mode set to auto
Desirable - Dynamic trunking mode set to desirable
Nonegotiate - Permanent trunking mode, but DTP frames are not sent across the trunk
117
What is VTP?
VTP is a Cisco proprietary virtual trunking protocol - Allows switches to advertise VLAN information between other members of the same VTP domain - Allows consistent view of the switched network across all switches.
118
What are the 3 separate VTP modes?
Client mode - Cannot modify, create, or delete VLANs. Also VTP clients cannot retain VLAN configuration information upon reboot
Server mode - VLANs can be created, modified, and deleted. Changes are advertised to all switches in the VTP domain. VLAN configuration information is kept in NVRAM
Transparent mode - Forward VTP advertisements received from other switches, but do not process the information contained in those ads. VLANs can be created, deleted, and modified, but those changes are not advertised, and are therefore locally significant only.
119
What are the 4 types of memory used in switches and routers, and what is the purpose of each one.
1) ROM - Stores the router's bootstrap startup program, operating system software, and POST
2) Flash Memory - IOS images are stored here - content is retained by the router on reload
3) RAM - Stores operational information such as routing tables and the running configuration file - content is lost when powered down or reloaded
4) NVRAM - Holds routers startup configuration - Contents are retained when the router is powered down or reloaded.
