4A0-105 practice question 23 of 25

MC-LAG is only supported on network ports.

Full set: 156 questions
Answer options
A: TRUE
B: FALSE
Correct Answer:
FALSE
Explanation

The statement is incorrect. Multi-Chassis Link Aggregation (MC-LAG) on Nokia Service Routers is a high-availability feature applicable to Link Aggregation Groups (LAGs). The physical member ports of these LAGs can be configured in either access mode or network mode. This allows MC-LAG to provide resilient connections not only for network-to-network interfaces but also for customer-facing services where ports are typically in access mode (e.g., for VPLS or Epipe services terminating in a Service Access Point (SAP) on the MC-LAG).

Why Incorrect

The statement "True" is incorrect because it imposes a limitation that does not exist. The SR OS implementation explicitly supports configuring ports within an MC-LAG in access mode to provide resilient service delivery to end-customer devices, in addition to network mode for core-facing links.

References

1. Nokia 7x50 SR OS R21.10.R1 Layer 2 Services and EVPN Guide, Document Part Number: 3HE 17489 AAAD TQZZA, Edition 01. In the "MC-LAG" chapter, the guide details the configuration of services over MC-LAG. For example, the section "VPLS SAPs on MC-LAG" implicitly confirms the use of access ports by describing how to create a Service Access Point (SAP), which is an access-mode construct, on an MC-LAG. It states, "A VPLS service can have SAPs on MC-LAG." This is only possible if the underlying LAG ports are in access mode.

2. Nokia 7750 Service Router Services Configuration Guide, Release 16.0.R1, Document Part Number: 3HE 10151 AAAC TQZZA, Edition 01. The "Multi-Chassis LAG" chapter describes its application for various services. In the section "MC-LAG Support for Business Services", it details how MC-LAG provides access redundancy for VLL, VPLS, and IES services. Providing access redundancy for these services requires the ports to be configured in access mode. For instance, it states, "MC-LAG provides a solution to provide redundant access to a VPLS network from a CE device." This confirms support beyond just network ports.

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