Static Route Calculator
Build a static route from a destination and prefix, and see whether its administrative distance beats the dynamic protocol.
Inputs
Network Address
10.20.30.0
Subnet Mask
255.255.255.0
Wildcard Mask
0.0.0.255
Which Route Installs
Static route installs — AD 1 beats 110
Acts as a Floating Static
No — it is the preferred path while the next hop is reachable
Administrative Distance Used
1
Step by step
Values used
Destination network = 10.20.30.0; Prefix length = 24 bits; Static route administrative distance = 1; Competing dynamic protocol = OSPF (AD 110)
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.
Network Address
= 10.20.30.0
Subnet Mask
= 255.255.255.0
Wildcard Mask
= 0.0.0.255
Which Route Installs
= Static route installs — AD 1 beats 110
Acts as a Floating Static
= No — it is the preferred path while the next hop is reachable
Administrative Distance Used
= 1
How it works
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.
Formula
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.
- AD
- Administrative distance — connected 0, static 1, eBGP 20, EIGRP 90, OSPF 110, RIP 120, iBGP 200
- wildcard mask
- Inverted mask, used in ACL and route-map match statements
- floating static
- A static route given a distance above the dynamic protocol so it only acts as backup
Frequently Asked Questions
How is Static Route calculated?
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.
Why does Static Route matter?
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.
What values do I need to enter?
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.
Why does my /32 static beat a more specific OSPF route?
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.