nerdexam
Cisco

300-730 · Question #175

Which configuration sets up spoke-to-spoke dynamic tunnels of FlexVPN?

The correct answer is A. The ip nhrp redirect command is needed on the hub router virtual-template interface. The ip nhrp redirect command on the hub's virtual-template interface is the required configuration to enable spoke-to-spoke dynamic tunnels in FlexVPN.

Site-to-site VPNs on Routers and Firewalls

Question

Which configuration sets up spoke-to-spoke dynamic tunnels of FlexVPN?

Options

  • AThe ip nhrp redirect command is needed on the hub router virtual-template interface.
  • BThe tunnel mode must be IPsec between spoke and hub routers.
  • CThe transform set mode must be tunnel mode between hub and spoke routers.
  • DThe ip nhrp nhs command is needed on spoke routers tunnel interface.

How the community answered

(41 responses)
  • A
    73% (30)
  • B
    2% (1)
  • C
    10% (4)
  • D
    15% (6)

Why each option

The ip nhrp redirect command on the hub's virtual-template interface is the required configuration to enable spoke-to-spoke dynamic tunnels in FlexVPN.

AThe ip nhrp redirect command is needed on the hub router virtual-template interface.Correct

When the hub receives a packet from one spoke destined for another spoke, the ip nhrp redirect command causes it to send an NHRP redirect message back to the source spoke, signaling it to build a direct dynamic tunnel to the destination spoke. This redirect mechanism is the core enabler of spoke-to-spoke dynamic connectivity in FlexVPN and must be applied on the hub's virtual-template interface.

BThe tunnel mode must be IPsec between spoke and hub routers.

Tunnel mode IPsec is a transport-layer encapsulation choice and does not control whether dynamic spoke-to-spoke tunnel establishment occurs.

CThe transform set mode must be tunnel mode between hub and spoke routers.

The transform set mode (tunnel vs. transport) affects ESP encapsulation but plays no role in initiating or enabling dynamic spoke-to-spoke tunnel negotiation.

DThe ip nhrp nhs command is needed on spoke routers tunnel interface.

The ip nhrp nhs command configures a spoke to register with its NHS hub for address resolution, which is a prerequisite for the NHRP infrastructure but does not itself enable spoke-to-spoke dynamic tunnels.

Concept tested: FlexVPN spoke-to-spoke dynamic tunnels using NHRP redirect

Source: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_conn_dmvpn/configuration/xe-16/sec-conn-dmvpn-xe-16-book/sec-conn-dmvpn-flexvpn.html

Topics

#FlexVPN#spoke-to-spoke#ip nhrp redirect#dynamic tunnels

Community Discussion

No community discussion yet for this question.

Sign up to join the discussion
Full 300-730 Practice