Free Cisco 400-251 Exam Dumps Questions & Answers

What us the most common IoT threat vector?

• A.  Attacks against programming errors in loT devices
• B.  Insertion of invalid inputs that cause denial of service
• C.  Human error and social engineering to access supervisory control systems
• D.  Physical access to loT devices that are installed in non-secure locations

Which statement about securing connection using MACsec is true?

• A.  It secures connection between two supplicant clients
• B.  The ISAKMP protocol is used to manage MACSec encryption keys
• C.  It provides network layer encryption on a wired network
• D.  A Switch configured for MACSec can accept MACSec frames from the MACSec client
• E.  It is implemented after a successful MAB authentication of supplicant
• F.  The Switch uses session keys to calculate encrypted packet ICV value for the frame integrity check

Which of the following statements correctly describe how DMVPN can be used to provide network segmentation over public transport networks?

• A.  The vrf forwarding command under the tunnel interface is used to associate encrypted packets with a VRF
• B.  DMVPN can be used to transport MPLS packets inside of an mGRE tunnel
• C.  The tunnel vrf command under the tunnel interface is used to associate clear text data packets with a VRF
• D.  The DMVPN hub and spokes must use the same VRF for a given DMVOB cloud
• E.  The front door VRF for DMVPN is defined under the isakmp profile

Which description of the AES encryption algorithm is true?

• A.  It uses three encryption keys of lengths 126. 192. and 256
• B.  Theoretically 3DES is more secure than AES
• C.  It does not use the substitution and permutation principle
• D.  lt uses the block of 128 bits
• E.  It provides only data integrity
• F.  Reapplying the same encryption key three times makes rt less vulnerable than 3DES

ISE is configured to use MsCHAPv2 inner method for PEAP authentication of users. What set of credentials needs to be exchanged between ISE and the client for successful establishment of the PEAP tunnel and subsequent authentication?

• A.  Identify certificate from ISE, Machine Identify certificate from the client and username and Password of the user
• B.  Username and Password from ISE and the client
• C.  Identify Certificate from ISE and user Identity certificate from the client
• D.  Identify certificate from ISE and Username and password of the user from the client