A service provider is in the process of providing Layer 2 and Layer 3 VPN services through a MPLS LDP-enabled backbone.
With load increasing in the service provider domain, scalability become the most important.
Based on the local label allocation filtering feature, which is the lower subset of prefixes must be selected to meet these requirements?
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A. B. C. D.A.
In a MPLS LDP-enabled backbone, the service provider is providing Layer 2 and Layer 3 VPN services, and with the increase in load, scalability becomes the most important factor to consider. In this context, the local label allocation filtering feature can be used to improve scalability and reduce the amount of label space needed for forwarding traffic.
The local label allocation filtering feature allows a service provider to filter which prefixes will be allocated a local label on each router in the network. By doing so, the service provider can limit the number of labels that need to be distributed throughout the network, improving scalability.
In the given scenario, the question is asking which subset of prefixes should be selected to meet the scalability requirements. The options are:
A. RR, P, and PE loopbacks that are used as BGP next hop B. all/32 prefixes advertised in the IGP C. P and PE loopbacks that are used as BGP next hop D. CE loopbacks only that are used as BGP next hop.
Option A includes loopbacks of the Route Reflector (RR), Provider (P), and Provider Edge (PE) routers that are used as BGP next hop. These loopbacks are typically used for BGP peering and routing, so filtering them may not be the best choice for scalability. Moreover, not all routers in the network will have these loopbacks, so filtering them may not provide a significant reduction in label space.
Option B suggests filtering all/32 prefixes advertised in the Interior Gateway Protocol (IGP). This option may not be feasible as it would lead to a significant reduction in the routing table and may impact the overall network operation.
Option C includes loopbacks of Provider (P) and Provider Edge (PE) routers that are used as BGP next hop. This option is a more targeted approach than option A and can reduce the amount of label space needed for forwarding traffic in the network.
Option D suggests filtering only Customer Edge (CE) loopbacks that are used as BGP next hop. This option may not be practical as it would depend on the network topology and the number of customers, and would not necessarily provide a significant reduction in label space.
Therefore, the best option in this scenario would be C, which suggests filtering loopbacks of Provider (P) and Provider Edge (PE) routers that are used as BGP next hop, to improve scalability and reduce the amount of label space needed for forwarding traffic.