单选题What is the port number of the IPsec Authentication Header packet？（）A IP protocol 50B TCP port 51C UDP port 50D IP protocol 51E UDP port 51F TCP port 50

第1题：

What is the port number of the IPsec Authentication Header packet？（）

• A、IP protocol 50
• B、TCP port 51
• C、UDP port 50
• D、IP protocol 51
• E、UDP port 51
• F、TCP port 50

第2题：

IPSec VPN is a widely-acknowledged solution for enterprise network. Which three IPsec VPNstatements are true？（）

• A、IKE keepalives are unidirectional and sent every ten seconds
• B、IPsec uses the Encapsulating Security Protocol （ESP） or the Authentication Header （AH）protocol for exchanging keys
• C、To establish IKE SA, main mode utilizes six packets while aggressive mode utilizes only threepackets
• D、IKE uses the Diffie-Hellman algorithm to generate symmetrical keys to be used by IPsec peers

第3题：

第4题：

What value is primarily used to determine which port becomes the root port on each nonroot switch in a spanning-tree topology?（）

• A、lowest port MAC address
• B、port priority number and MAC address.
• C、VTP revision number
• D、highest port priority number.
• E、path cost

第5题：

What does the number one 1 represent for interface fe-0/0/1？（）

• A、port number
• B、PCI slot number
• C、channel number
• D、virtual PIC number

第6题：

What value is primarily used to determine which port becomes the root port on each nonroot switch in a spanning-treetopology?（）

• A、lowest port MAC address
• B、port priority number and MAC address.
• C、VTP revision number
• D、highest port priority number.
• E、pathcost

第7题：

What is not a difference between VPN tunnel authentication and per-user authentication?（）

• A、VPN tunnel authentication is part of the IKE specification. 
• B、VPN tunnel authentication does not control which end user can use the IPSec SA (VPN tunnel).
• C、User authentication is used to control access for a specific user ID, and can be used with or without a VPN tunnel for network access authorization. 
• D、802.1X with EAP-TLS (X.509 certificates) can be used to authenticate an IPSec tunnel.

第8题：

What is the port number of an IPsec Encapsulating Security Payfoad packet？（）

• A、UOP port 50
• B、IP protocol 51
• C、TCP port 51
• D、TCP port 50
• E、IP protocol 50
• F、UDP port51

第9题：

Which three security concerns can be addressed by a tunnel mode IPsec VPN secured by ESP?（） (Choose three.)

• A、data integrity
• B、data confidentiality
• C、data authentication
• D、outer IP header confidentiality
• E、outer IP header authentication

第10题：

In a network using cisco autonomous access points running wds. What port is used for authentication by the local authentication service on an access point？（）

• A、1813
• B、1645
• C、1646
• D、1812