JN0-664 Exam QuestionsBrowse all questions from this exam

JN0-664 Exam - Question 50


You have an L2VPN connecting two CEs across a provider network. The CEs and provider network are configured with the default MTU setting. You use the ping command from one CE to the other CE with a size of 1500 bytes.

In this scenario, which statement is correct when using the ping command?

Show Answer
Correct Answer: C

In an L2VPN scenario with the default MTU setting, the maximum transmission unit (MTU) for both the customer edge (CE) devices and the provider network is typically set to 1500 bytes. However, MPLS encapsulation adds additional overhead, which increases the total frame size beyond 1500 bytes. Since Layer 2 VPNs do not support fragmentation within the provider network, any packet exceeding the MTU size will be silently discarded without an error message. Therefore, when a ping command with a payload of 1500 bytes is sent in this scenario, the packet will exceed the allowable frame size and will be silently discarded.

Discussion

3 comments
Sign in to comment
bololbnoOption: C
Apr 8, 2024

answer is C. according to juniper documentation configuring L2VPN. Layer 2 VPNs don’t support fragmentation in the provider network. It is critical that the provider network supports the largest frame that the CE devices can generate after the MPLS and virtual routing and forwarding (VRF) labels are added by the PE devices. This example leaves the CE devices at the default 1500-byte maximum transmission unit (MTU) while configuring the provider core to support a 4000 byte MTU. This configuration avoids discards by ensuring the CE devices cannot exceed the MTU in the provider’s network.

yaronasOption: C
Apr 10, 2024

answer is C

mad_maranOption: C
Apr 13, 2024

Answer is C