CCNP R&S Question of the Week: IPsec Modes

Which IPsec mode will encrypt a GRE tunnels and reduced overhead?

A. 3DES
B. multipoint GRE
C. tunnel
D. transport

Reveal Answer

Answer: D.

When IPSec is running in tunnel mode, a new IPv4 header will be created, followed by the AH and/or ESP header(s), then the original IP header.  In transport mode, there is no new IPv4 header, the AH and/ESP header(s) are added above the original IP header.  Therefore there is reduced overhead of adding an additional IP header.

 

Related Courses
ROUTE – Implementing Cisco IP Routing v2.0
SWITCH – Implementing Cisco IP Switched Networks v2.0
TSHOOT – Troubleshooting and Maintaining Cisco IP Networks v2.0

Related Certification
CCNP Routing and Switching

CCNP R&S Question of the Week Series

• CCNP R&S Question of the Week: IPv6
• CCNP R&S Question of the Week: BGP Attribute
• CCNP R&S Question of the Week: Gateway of Last Resort
• CCNP R&S Question of the Week: Routing Protocols into OSPF
• CCNP R&S Question of the Week: BPDU Guard
• CCNP R&S Question of the Week: Private VLANs
• CCNP R&S Question of the Week: Blocking to Forwarding State
• CCNP R&S Question of the Week: FTP to HTTP
• CCNP R&S Question of the Week: Alerts
• CCNP R&S Question of the Week: Configuration Sequence
• CCNP R&S Question of the Week: TCP Traffic
• CCNP R&S Question of the Week: IPv4 and IPv6
• CCNP R&S Question of the Week: clear ip route
• CCNP R&S Question of the Week: IPv6 Traffic Filter Impact
• CCNP R&S Question of the Week: EtherChannel
• CCNP R&S Question of the Week: Interface FastEthernet0/1
• CCNP R&S Question of the Week: Directly Connected CDP Devices
• CCNP R&S Question of the Week: IPsec Modes

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