A network technician is configuring a branch office router connected to headquarters via two WAN links. The primary connection uses a static route targeting the headquarters network , configured with an administrative distance of . A secondary backup connection runs Open Shortest Path First (OSPF) to reach the same network prefix. During testing, traffic unexpectedly routes through the secondary OSPF link even while the primary link remains operational. Which configuration change will ensure that traffic prioritizes the primary static route over the backup OSPF route?
- Reduce the administrative distance of the static route to a value lower than .Answer
- BDecrease the interface metric cost on the secondary OSPF link to .
- CReconfigure the primary static route using NAT Overload (PAT) on the outgoing WAN interface.
- DChange the subnet mask of the static route to to broaden prefix matching.
Answer
Reduce the administrative distance of the static route to a value lower than 110.
When a router receives multiple routes to the exact same destination prefix from different sources, it evaluates Administrative Distance (AD). Standard OSPF has an AD of 110. Because the static route was manually set to an AD of 120, the router preferred OSPF. Lowering the static route's AD below 110 (for example, to 1) restores its priority over the OSPF route.
Step-by-Step Solution
Key Concept
Administrative Distance vs Protocol Metrics in Route Selection
Estimated Time:1m 30s