Q&A Hero

Q: What is a potential problem with having too many APs in a given area?a. refraction c. multipathb. fading d. co-channel interference

Q: In which frequency range are you likely to find WLANs?a. 30-300 GHz c. 2.9-30 GHzb. 174-328 MHz d. 3-30 MHz

Q: Which of the following pairs represents a medium frequency band and its common use?a. 300 KHz-3MHz, AM radio b. 144-174 MHz, TV channels c. 30-300 KHz, cordless phonesd. 3-30 MHz, CB and shortwave radio

Q: Which of the following is true about infrared transmissions?a. directed IR transmission relies on reflected light b. diffused IR transmission requires emitter and detector to be aligned c. the intensity of the light pulse indicates the on or off status of each bitd. IR transmissions have speeds up to 25 Mbps.

Q: Which of the following is true about RF transmissions?a. EM radiation is measured in volts b. frequency has an inverse relationship with wavelength c. frequency is the distance between wavesd. cooler objects produce higher-frequency radiation than hotter objects

Q: Which of the following is defined as the maximum departure of a wave from the undisturbed state?a. amplitude c. frequencyb. spectrum d. wavelength

Q: The 802.11i standard maps to the WPA2 security protocol.

Q: The Independent Basic Service Set is a wireless network that uses an AP.

Q: The Fresnel zone is the dispersal pattern of waves as they travel from sending to receiving antennas.

Q: RF signals can pass through walls and other objects while IR cannot.

Q: In wireless networks, infrared signals are used most often for data communications.

Q: Describe how RF waves are transmitted and received by an antenna.

Q: Describe OFDM.

Q: Describe two of the four methods of digital signal modulation.

Q: Describe two of the three methods of analog modulation.

Q: What is a MAC tag and how does it work?

Q: What three conditions must be true to make a hashing algorithm secure?

Q: How does an asymmetric algorithm differ from a symmetric algorithm?

Q: Compare and contrast block cipher with stream cipher.

Q: How does the key size affect the strength of an encryption algorithm?

Q: What is a hash value and how does it verify message integrity?

Q: What does a key derivation do?

Q: What is a Feistel network and what is its purpose?

Q: Describe the exclusive OR function.

Q: a. AES f. XOR functionb. block cipher g. IPsecc. ciphertext h. key managementd. cryptanalysis i. plaintexte. DES j. stream cipher1/ the study of breaking encryption methods2/ unreadable text, programs that do not execute, and graphics you cannot view3/ A set of standard procedures that the Internet Engineering Task Force (IETF) developed for enabling secure communication on the Internet4/ a type of encryption algorithm that encrypts one bit at a time5/ the current U.S. government standard for cryptographic protocols6/ readable text, programs that execute, and graphics you can view7/ an older protocol composed of a 16-round Feistel network with XOR functions, permutation functions, 64 S-box functions, and fixed key schedules8/ a way to prevent keys from being discovered and used to decipher encrypted messages9/ a cryptographic primitive based on binary bit logic and used as a linear mixing function, combining values for use in further computations10/ a type of encryption algorithm that encrypts groups of cleartext characters

Q: ______________ cryptanalysis is applicable to block ciphers that use a substitution-permutation network including Rijndael, Twofish, and IDEA.

Q: Digital ____________________ security vulnerabilities are mostly associated with the IT infrastructure required to support interoperability.

Q: A ________________ occurs when computing the MD5 algorithm with two different initialization vectors produces the same hash value.

Q: A ______________ value is a fixed-size string representing the original input's contents.

Q: ______________________ is achieved when neither party can plausibly deny its participation in message exchanges.

Q: Which of the following is a type of cryptanalysis that applies primarily to block ciphers but can also be used against stream ciphers and hashing functions and works by examining how differences in input affect the output?a. integral c. related keyb. differential d. XSL

Q: Which component of IPsec enables computers to exchange keys to make an SA?a. IKE c. Oakleyb. ISAKMP d. IPsec driver

Q: At which layer of the OSI model does IPsec work?a. Two c. Fourb. Three d. Six

Q: Which of the following was developed as a way of enabling Web servers and browsers to exchange encrypted information and uses a hashed message authentication code to increase security?a. SSH c. TLSb. SSL d. IPsec

Q: What is a downside to using Triple DES?a. uses only a 56-bit key c. using three keys decreases securityb. goes through three rounds of encryption d. requires more processing time

Q: Which of the following is a current standard for PKI that specifies a strict hierarchical system for CAs issuing certificates?a. PKCS #2 c. DESb. X.509 d. SHA-1

Q: Which of the following best describes a CRL?a. a published listing of invalid certificates b. serve as a front end to users for revoking certificates c. a file that contains information about the user and public keyd. keeps track of issued credentials and manages revocation of certificates

Q: Which of the following is true about asymmetric cryptography?a. the private key can be used to encrypt and decrypt a message b. a shared key is used to encrypt all messages and the private key decrypts them c. a single key is used and is transferred using a key management systemd. the public key is used to encrypt a message sent to the private key owner

Q: What is the most likely weak link when using asymmetric encryption for verifying message integrity and nonrepudiation?a. the use of the sender's private key b. the hashing algorithm used to generate a message digest c. the source of the public keysd. the integrity of the private keys

Q: Which of the following is the first step in the digital signature process where Mike sends a message to Sophie?a. a message digest of Mike's message is calculated using a hashing algorithm b. Sophie compares the message digest she calculated to Mikes's message c. Sophie encrypts Mike's message with Mike's public keyd. the message digest is encrypted by Mike's private key

Q: Which of the following is true about Message Authentication Code.a. it uses asymmetric encryption b. the key is sent to the receiver securely c. is uses PKI and certificatesd. it uses a private and public key

Q: Which of the following makes a single pass on data and generates a 128-bit hash value displayed as a 32-character hexadecimal number and is used in VPNs?a. RSA c. RC4b. Message Digest 5 d. Twofish

Q: Which of the following is described as a 64-bit block cipher composed of a 16-round Feistel network and key-dependent S-box functions?a. Twofish c. Blowfishb. RC4 d. Rijndael

Q: Which of the following is true about encryption algorithms?a. their strength is tied to their key length b. not vulnerable to brute force attacks c. block ciphers encrypt one bit at a timed. asymmetric algorithms use a single key

Q: Which of the following is commonly used for verifying message integrity?a. registration authority b. CRL c. pseudorandom number generatord. hashing function

Q: Which of the following is true about PRNGs?a. they are not completely random b. their state is measured in bytes c. the shorter the state, the longer the periodd. they can never produce the same value

Q: Which of the following best describes a one-way function?a. a bit string that prevents generation of the same ciphertext b. random bits used as input for key derivation functions c. generates secret keys from a secret valued. easy to compute but difficult and time consuming to reverse

Q: Which type of function is used in cryptography?a. Not AND c. NORb. permutation d. X-box

Q: Which of the following is true about cryptographic primitives?a. each performs several tasks b. a single primitive makes up an entire cryptographic protocol c. primitives are usually not the source of security failuresd. a primitive that provides confidentiality usually also provides authentication

Q: Which of the following is NOT a critical goal of information security?a. confidentiality c. authenticationb. scalability d. nonrepudiation

Q: In a passive attack, cryptanalysts eavesdrop on transmissions but don"t interact with parties exchanging information.

Q: Because IPsec Security Associations are bidirectional, only one need be established between two parties.

Q: The standardization of cryptographic protocols discourages attackers from trying to break them.

Q: A hash value is a variable-length string of symbols and numbers representing the original input's contents.

Q: Encrypted files can be transmitted in both electronic form and as written messages.

Q: Describe antispoofing logging and how you can prevent it with ACLs.

Q: Where in an internetwork should extended ACLs be applied?

Q: Describe ACLs.

Q: Define route summarization.

Q: Define metric and give three examples of common metrics that routers use.

Q: What is a distance-vector routing protocol? Give one example.

Q: What is a stub router and where would you find one?

Q: What is a dynamic route?

Q: Describe how a computer uses its ARP table and the ARP protocol when preparing to transmit a packet to the local network.

Q: a. ACE f. inverse maskb. ARP table g. metricsc. banner h. routingd. console port i. stub routere. convergence j. virtual terminal1/ the port on a Cisco device that permits direct physical access from a nearby computer using the serial RS-232 protocol2/ cost values that help routers assess the desirability of a link3/ virtual session access points for simultaneous access to a Cisco device4/ a state in which all routers on a network have up-to-date routing tables5/ a router that connects a stub network to the larger network6/ a network system tool that lists the MAC and IP address resolutions of otherdevices on the network, making the resolution process more efficient7/ the number in an access control list that specifies which part of an IP address is considered significant8/ an individual rule in an ACL9/ the process of transporting packets of information across a network from thesource node to the destination node10/ a message, usually a warning about appropriate use, presented to users of a digital system before authentication

Q: The enable ___________ password uses type 5 encryption and overrides the enable password.

Q: Rather than using classful routing, ________________ subnet masks allow you to divide your network into different sizes to make better use of available addresses.

Q: ____________ routes are manually configured routes that direct all packets not specifically configured in the routing table.

Q: An ARP broadcast is sent to the local subnet in an attempt to discover the destination computer's ______________ address.

Q: During the routing process, the router strips off ______________________ layer header information and then examines the Network layer address.

Q: Which protocol that runs on Cisco routers shares information between Cisco devices?a. CDP c. bootpb. TCP d. SSH

Q: What Cisco router command encrypts all passwords on the router?a. enable secret password c. crypto key passwordsb. secure passwords enable d. service password-encryption

Q: What remote shell program should you use if security is a consideration?a. rlogin c. rcpb. ssh d. rsh

Q: Which of the following types of password prevents a user from accessing privileged exec mode on a Cisco router?a. console c. enableb. AUX d. TTY

Q: Which of the following is an open standard used for authentication on Cisco routers?a. RADIUS b. ATM c. CHAPd. ACE

Q: Which of the following is a command you would find in an antispoofing ACL for network 172.31.0.0/16?a. permit ip any 172.31.0.0 0.0.255.255 log b. deny TCP 172.31.0.0 0.0.0.0 any log c. deny ip 172.31.0.0 0.0.255.255 any logd. permit icmp any any redirect

Q: What should you set up if you want to store router system log files on a server?a. AAA server b. syslog server c. TTY connectiond. buffered logging

Q: Which of the following is true about extended IP ACLs?a. the "˜established" keyword is not available except on standard ACLs b. you can apply multiple outbound ACLs on a single interface c. the default inverse mask for the source is 0.0.0.0d. they should be applied to an interface close to the traffic source

Q: Which of the following is true about standard IP ACLs?a. they can filter on source and destination IP address b. they automatically apply to all active interfaces c. a 0.0.0.0 inverse mask means all bits are significantd. they can filter on IP address and port

Q: Which of the following is true about ACLs on Cisco routers?a. there is an implicit deny any statement at the end of the ACL b. there is an explicit permit any statement at the beginning of the ACL c. ACLs are processed in reverse order so place high priority statements lastd. ACLs bound to an interface apply to inbound and outbound traffic by default