Build a static route from a destination and prefix, and see whether its administrative distance beats the dynamic protocol.
Route selection is two-stage: the longest matching prefix wins outright, and administrative distance only breaks ties between protocols offering the same prefix. Raising a static route's distance above the dynamic protocol turns it into a floating static that sits dormant until the dynamic path disappears. Getting the distance wrong is how a backup DSL static route ends up carrying production traffic, or how a supposed backup never installs at all because it was left at the default distance of 1.
Static Route
The network address is destination AND mask; the route installs when its administrative distance is lower than every competing protocol's, and longest prefix match is applied before distance.
The network address is destination AND mask; the route installs when its administrative distance is lower than every competing protocol's, and longest prefix match is applied before distance. Route selection is two-stage: the longest matching prefix wins outright, and administrative distance only breaks ties between protocols offering the same prefix. Raising a static route's distance above the dynamic protocol turns it into a floating static that sits dormant until the dynamic path disappears.
Getting the distance wrong is how a backup DSL static route ends up carrying production traffic, or how a supposed backup never installs at all because it was left at the default distance of 1.
This calculator takes 4 inputs: Destination network, Prefix length, Static route administrative distance, Competing dynamic protocol. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
It probably is not more specific. Longest prefix match runs first, so a /32 static always beats an OSPF /24 regardless of distance — distance is only consulted when the prefixes are identical.