4A0-115: Nokia Ethernet Virtual Private Network ServicesDemo

By Nokia · Question Mode

QuestionQ1

EVPN for Layer-3 services

In the exhibit, EVPN-IRB is configured using the interface-ful unnumbered model. Which of the following statements about the route advertisement is FALSE?

Question Image

  • A PE1 advertises an EVPN IP-Prefix route for prefix 10.10.1.0/24 to PE3. The BGP update includes MAC-01 as an overlay index.
  • B PE1 advertises an EVPN MAC route for MAC-01 to PE3. The BGP update includes the route-target value configured for VPRN 15.
  • C PE3 advertises a VPN-IPv4 route for prefix 10.10.1.0/24 to PE4. The BGP update Includes an MPLS service label.
  • D PE4 advertises an EVPN IP-Prefix route for prefix 10.10.1.0/24 to PE2. The BGP update includes MAC-04 as an overlay index.
Explanation

In the interface-ful unnumbered EVPN-IRB model, EVPN Type-5 (IP-Prefix) routes are advertised under the route target(s) of the Layer-3 IP-VRF (VPRN) service, carrying the advertising PE's own IRB MAC address as the overlay index. However, the EVPN Type-2 MAC/IP route needed to resolve that MAC overlay index is generated and exported by the Layer-2 bridging instance (the R-VPLS/EVI) to which the IRB is bound — in this topology, R-VPLS 20 on PE1 — using that bridge instance's own configured route target, not the route target configured on VPRN 15. Therefore the claim that PE1's MAC route advertisement for MAC-01 carries the route target configured for VPRN 15 is incorrect, since the Layer-2 EVI and the Layer-3 VPRN are distinct services with independent route-target configuration.

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