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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. DoS attacks are more probable with this mode.






2. IPsec implements using a shim header between L2 and L3






3. You check it by hashing data and appending the hash value to the data as you send it across the network to a peer.






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






5. The protocol of choice for key management and establishing security associations between peers on the Internet.






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






7. Uses protocol number 51.






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






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






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






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






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






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






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






15. Verify whether the data has been altered.






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






17. Provides authentication and encryption of the payload.






18. Integrity checks are done


19. 'Developed in 1977 by Ronald Rivest - Adi Shamir - and Leonard Adleman (therefore - RSA).'






20. 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.






21. Used for integrity checks on peer and data sent by peer and for authentication checks.






22. 'A 56-bit encryption algorithm - meaning the number of possible keys






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






24. 'often called public-key algorithms - do not rely on a randomly generated shared encryption key; instead - they create two static keys. These static keys are completely different - but mathematically bound to each other; what one key encrypts - the o






25. Uses protocol number 50.






26. '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






27. Takes variable-length clear-text data to produce fixed-length hashed data that is unreadable.






28. Turns clear-text data into cipher text with an encryption algorithm. The receiving station decrypts the data from cipher text into clear text. The encryption key is a shared secret key that encrypts and decrypts messages.






29. Used in IPsec for two discreet purposes:






30. That authenticate data packets and ensure that data is not tampered with or modified.






31. ' is defined in RFC 3174. has as output a 160-bit value -'






32. 'Three keys encrypt the data - which results in a 168-bit encryption key. The sending device encrypts the data with the first 56-bit key.'






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






34. 'The sending device decrypts the data with the second key - which is also 56 bits in length.'






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






36. 'in most cases - this mode is preferred with certificates.'






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






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






39. Act of encapsulating a packet within another packet.






40. Main disadvantage of asymmetric algorithms is that they are slow.






41. 'establishes ISAKMP SA in three messages -because it negotiates a ISAKMP policy and a DJ nonce exchange together.'






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






43. 'MACs with hash algorithms -'






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






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






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






47. Key exchange for IPSEC






48. 'Encryption - where Peer X uses Peer Y






49. 'is a more secure version of MD5 - and hash-based message authentication codes (HMAC) provides further security with the inclusion of a key-based hash.'






50. Uses the D-H algorithm to come to agreement over a public network.