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CCIE Sec Encryption Ipsec

Subjects : cisco, it-skills, ccie
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. You check it by hashing data and appending the hash value to the data as you send it across the network to a peer.






2. IPSec SAs are negotiated and protected by the existing IPsec SA.






3. The DES algorithm that performs 3 times sequentially.






4. This mode does not support identity protection or protection against clogging attacks and spoofing.






5. 'When using the hash-based key function -'






6. 'defines the mode of communication - creation - and management of security associations.'






7. Main mode establishes ISAKMP security association in six messages and performs authenticated D-H exchange.






8. IPSEC tunnels data through IP using one of two protocols?






9. Has a trailer which identifies IPsec information and ESP integrity-check information.






10. 'Encryption - where Peer X uses Peer Y






11. 'Digital signatures. Peer X encrypts a hash value with his private key and then sends the data to Peer Y. Peer Y obtains Peer X






12. The receiving device then encrypts the data with the second key.






13. The receiving device decrypts the data with the third key.






14. Uses IKE for key exchange.






15. 'group 5 identifies a 1536-bit key - provides for highest security but is the slowest of all groups.'






16. 'Created by NIST in 1994 - is the algorithm used for digital signatures but not for encryption.'






17. 'Message digest algorithms have a drawback whereby a hacker (man in the middle) can intercept a message containing the packet and hash values - then re-create and transmit a modified packet with the same calculated hash to the target destination.'






18. 'including Internet Security Association and Key Management Protocol (ISAKMP) - Secure Key Exchange Mechanism for the Internet (SKEME) - and Oakley.'






19. Verify whether the data has been altered.






20. IPSEC performs this function by using a sequence field in the IPsec header combined with integrity checks.






21. 'Finally - the receiving devices decrypt the data with the first key.'






22. Data integrity is the process of making sure data is not tampered with while it






23. Uses protocol number 51.






24. 'provides everything required to securely connect over a public media - such as the Internet.'






25. Drawback of this is that the hash is passed unencrypted and is susceptible to PSK crack attacks.






26. 'can be achieved using one of three methods: preshared keys - encrypted nonces - or digital signatures.'






27. It uses UDP 500 and is defined by RFC 2409.






28. Can be implemented efficiently on a wide range of processors and in hardware.






29. 'MACs with hash algorithms -'






30. 'requires that the sender and receiver have key pairs. By combining the sender






31. 'has a Next Protocol field which identifies the next Layer 4 transport protocol in use - TCP or UDP'






32. 'key exchange is vulnerable to a man-in-the-middle attack. You can rectify this problem by allowing the two parties to authenticate themselves to each other with a shared secret key - digital signatures - or public-key certificates.'






33. Uses protocol number 50.






34. Negotiation of the ISAKMP policy by offering and acceptance of protection suites


35. Message of arbitrary length is taken as input and produces as output a 128-bit fingerprint or message digest of the input.






36. Used in government installs and was created to work with the SHA-1 hash algorithm.






37. One of the most popular tunneling protocols is






38. 'DSA is roughly the same speed as RSA when creating signatures - but 10 to 40 times slower when verifying signatures. Because verification happens more frequently than creation - this issue is worth noting when deploying DSA in any environment.'






39. Hybrid protocol that defines the mechanism to derive authenticated keying material and negotiation of security associations (SA).






40. It also provides protection for ISAKMP peer identities with encryption.






41. Provide authentication in Internet Key Exchange (IKE) Phase 2.






42. Benefits are that the preshared authentication can be based on ID versus IP address and the speed of the process.






43. A variable block- length and key-length cipher.






44. Key exchange for IPSEC






45. A






46. 'key lengths are 128 - 192 - or 256 bits to encrypt blocks of equal length.'






47. Where the original Layer 3 header and payload inside an IPsec packet is encapsulated. Tunnel mode does add overhead to each packet and uses some additional CPU resources.






48. 'group 1 identifies a 768-bit key - group 1 is faster to execute - but it is less secure -'






49. Negotiation of a shared secret key for encryption of the IKE session using the D-H algorithm


50. 'produces a 160-bit hash output - which makes it more difficult to decipher.'