A parks department upgraded campus uplinks from 1 Gbps to 100 Gbps and noticed OSPF still treats many links as equal-cost. What should they recalculate so interface costs stay meaningful?
Select an answer to reveal the explanation.
Short Explanation
OSPF cost is ‘reference bandwidth divided by link speed.’ If the reference stayed stuck in the 1G era, a 10G and a 100G can look the same. Raise the reference so the fat pipes actually look cheaper—and keep that value consistent domain-wide.
Full Explanation
OSPF interface cost defaults from reference-bandwidth / interface-bandwidth. After multi-gigabit upgrades, an outdated reference collapses many speeds into identical costs and weakens path selection. Raising auto-cost reference bandwidth (consistently on all OSPF routers) restores differentiation. BGP MED, STP priority, and EIGRP delay are not substitutes for OSPF reference-bandwidth tuning.