300-420 Exam Dumps : Designing Cisco Enterprise Networks

The multicast-replicator function is used to optimize multicast traffic distribution across Cisco SD-WAN. Cisco Catalyst SD-WAN multicast overlay design avoids forcing the ingress WAN Edge router to replicate every multicast packet to every remote receiver. Instead, multicast routes and receiver information are exchanged through OMP, and a WAN Edge can be designated as a multicast or OMP replicator. The replicator then distributes streams to interested receivers across the overlay, reducing bandwidth and processing pressure on the source-side edge. That is why multicast-replicator is the feature that optimizes WAN bandwidth for IGMP-driven multicast receiver traffic among WAN Edge routers in the same VPN. IGMPv2 is only the host-to-router group membership protocol and does not optimize overlay distribution by itself. A multicast RP is used in PIM sparse mode, but it is not the SD-WAN overlay replication feature. Multicast service routes advertise multicast service information, but the bandwidth-saving forwarding role is the replicator. Reference topics: Cisco SD-WAN multicast overlay, OMP multicast routes, multicast replicator, IGMP receiver joins.

The correct BGP design is to attach the well-known No-Export community to the prefixes that should not be advertised beyond the service provider boundary. Cisco BGP communities are policy attributes that allow routes to carry instructions or classifications across BGP peers. The No-Export community tells a receiving BGP speaker not to advertise the route outside its confederation or autonomous system. That behavior is exactly what is needed when branch prefixes may be exchanged with the provider but must not be propagated to the public Internet. The No-Advertise community is stronger: it prevents the route from being advertised to any BGP peer, which may block reachability even where the provider still needs to know the route. NOPEER is used for route-server or peering policy control and is not the clean answer for excluding branch prefixes from Internet propagation. Setting a generic “Internet community” is not a standard solution by itself. The architect should also ensure that outbound prefix filters and provider-side community support are documented in the service agreement. Reference topics: BGP communities, No-Export, No-Advertise, provider edge filtering, Internet route policy.

The selected command is correct because the port is already restricted to one manually learned MAC address, and the requirement is to let the switch dynamically learn the connected endpoint while retaining port-security control. In Cisco Catalyst port security, a static secure MAC address is manually configured, while a sticky secure MAC address is dynamically learned and then added to the running configuration. This design is useful on access ports where the administrator wants the operational convenience of dynamic learning but still wants the switch to enforce the maximum secure-address limit. Once the endpoint MAC is learned, subsequent frames from different source MAC addresses can trigger the configured violation action, such as protect, restrict, or shutdown. The command must therefore enable sticky learning on the secured interface rather than simply changing the maximum, disabling port security, or configuring a normal switching feature. This is an access-layer security function, not a routing or QoS function. Reference topics: Catalyst port security, secure MAC addresses, sticky learning, access port hardening, Layer 2 campus design.