MPLS OAM Ping Capabilities

B.

MPLS OAM (Operations, Administration, and Maintenance) Ping is a tool used to diagnose and test the connectivity of MPLS networks. It sends ICMP (Internet Control Message Protocol) echo requests to a destination and receives ICMP echo replies from that destination. The MPLS OAM Ping function is available in Cisco IOS routers and can be used to test the functionality of Label Switched Paths (LSPs) in MPLS networks.

Now, let's go through each option and see which one is true:

A. An LSP is not required for the reply to reach the ingress MPLS router. This statement is false. In order for the MPLS OAM Ping reply to reach the ingress MPLS router, an LSP must be present. MPLS OAM Ping works by sending an ICMP echo request packet with an MPLS label attached to it, which is then forwarded through the MPLS network using the LSP. The MPLS label is used to direct the packet along the correct path to reach the destination. When the packet reaches the destination, it is processed and an ICMP echo reply packet is generated. This reply packet is sent back along the same LSP to the ingress MPLS router.

B. An LSP breakage results in the ingress MPLS router never receiving any reply. This statement is true. If an LSP breakage occurs along the path between the ingress MPLS router and the destination, then the MPLS OAM Ping reply packet will not be able to reach the ingress router. In this case, the ingress router will never receive any reply from the destination. This is because the MPLS OAM Ping function relies on the LSP to deliver both the request and reply packets.

C. MPLS OAM Ping works solely with P2P LSPs. This statement is false. MPLS OAM Ping can be used with both point-to-point (P2P) and point-to-multipoint (P2MP) LSPs. With P2P LSPs, the MPLS OAM Ping function sends an ICMP echo request packet to a single destination. With P2MP LSPs, the MPLS OAM Ping function sends an ICMP echo request packet to multiple destinations simultaneously.

D. MPLS OAM Ping works solely with Cisco MPLS T. This statement is false. MPLS OAM Ping is a standard function in MPLS networks and is not specific to any vendor's implementation. It can be used with any MPLS network, including those built with Cisco MPLS T (Transport) technology.