Exhibit:R2 received an OSPF update from R1, and it received the same update from R3.

In the exhibit, R2 receives the same OSPF update from both R1 and R3. OSPF has mechanisms toprevent unnecessary processing of duplicate LSAs (Link-State Advertisements).

Step-by-Step Breakdown:

OSPF LSA Processing:

OSPF uses LSAs to exchange link-state information between routers. When a router receives an LSA, it checks if it already has a copy of the LSA in its Link-State Database (LSDB).

Duplicate LSAs:If R2 has already received and processed the update from R1, it willignore the update from R3because it already has the same LSA in its database. OSPF uses the concept of flooding, but it does not reprocess LSAs that it already knows about.

R2 Behavior:R2 will keep the update from R1 (the first one it received) and will ignore the same LSA from R3, as it is already in the LSDB.

Juniper Reference:

OSPF LSA Processing: Junos adheres to OSPF standards, ensuring that duplicate LSAs are not processed multiple times to avoid unnecessary recalculations.