Tag: Administrative distance

There are different documents and books which are claiming that Administrative distance for static routes configured using exit interface is 1 and for the static route configured using next-hop IP address Administrative distance is 0.

R1(config)#ip route 20.0.0.0 255.255.255.0 10.10.2.1
R1(config)#ip route 20.0.0.0 255.255.255.0 fastEthernet 0/0

This is not true. Both of them are having AD value of 1. The confusion is coming from the info that directly connected interface has AD of 0, but static route outbound that interface is having the AD of 1.

Administrative distance is the measure used by Cisco routers to help them decide how to select the best path when there’s more that one route to the same destination from different routing protocols. We can say that in this manner administrative distance shows the real reliability of a routing protocol in one system. It shows which routes are more important based on the routing protocol from which they derived. Each routing protocol is prioritized in order of most to least reliable using an administrative distance value. Don’t get confused, a lower numerical value is preferred. For example, an EIGRP with an administrative distance of 90 will be chosen over a RIP route with an administrative distance of 120 and over OSPF route with an administrative distance of 110 to.

Here is a table with all default administrative distances used by Cisco routers: