JN0-106: Junos, Associate (JNCIA-Junos) CertificationDemo

R1's only route for unmatched traffic is its default route (0.0.0.0/0) pointing to R2, while R2's route for the 10.1.0.0/16 supernet points back to R1. Since User A, B, and C only occupy the /24 subnets 10.1.0.0/24, 10.1.1.0/24, and 10.1.2.0/24 (each directly connected to R1), any destination within 10.1.0.0/16 that falls outside those specific /24s — such as 10.1.99.1 — is not matched by a direct route on R1. Traffic to such an address is forwarded via R1's default route to R2, and R2 then forwards it back to R1 via its static route for 10.1.0.0/16, since R1's directly connected subnets are more specific but do not cover 10.1.99.0/24. This ping-pong between the default route on R1 and the summary route on R2 produces a routing loop.