An engineer must design a solution to provide backup connectivity between two sites. The engineer plans to use an Internet connection but company policy requires the connection to be encrypted. Additi

The correct answer is A. GRE over IPsec. IPsec in its native transport or tunnel mode does not support multicast traffic because IPsec is a unicast protocol. GRE (Generic Routing Encapsulation) natively supports multicast and broadcast by encapsulating those packets inside a unicast GRE tunnel. Combining GRE with IPsec

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Question

An engineer must design a solution to provide backup connectivity between two sites. The engineer plans to use an Internet connection but company policy requires the connection to be encrypted. Additionally, there are several applications that utilize multicast to deliver video streams between the sites. Which technology should the design include?

Options

AGRE over IPsec
BIPsec direct encapsulation
CGETVPN
DDMVPN

How the community answered

(27 responses)

A
70% (19)
B
11% (3)
C
15% (4)
D
4% (1)

Explanation

IPsec in its native transport or tunnel mode does not support multicast traffic because IPsec is a unicast protocol. GRE (Generic Routing Encapsulation) natively supports multicast and broadcast by encapsulating those packets inside a unicast GRE tunnel. Combining GRE with IPsec satisfies both requirements: GRE carries the multicast video streams, and IPsec encrypts the entire GRE tunnel for security over the Internet. IPsec direct encapsulation (option B) drops multicast. GETVPN (option C) is designed for private MPLS networks and requires a Key Server - not suitable for Internet connectivity. DMVPN (option D) is optimized for hub-and-spoke or spoke-to-spoke designs and adds unnecessary complexity for a simple two-site backup link.

Topics

#VPN#GRE#IPsec#Multicast

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