CyberCertPrepNetwork FundamentalsSwitching & Routing BasicsEASYFree question
What is a static route's administrative distance on a Cisco router, and what happens when both a static route and an OSPF route exist for the same prefix?
- A.A static route has an administrative distance (AD) of 1 on Cisco IOS; OSPF routes have an AD of 110. Since lower AD is preferred, the static route wins and is installed in the routing table, with the OSPF route kept as a backup
- B.A static route has AD 0 on Cisco IOS; OSPF has AD 110; both routes are installed and traffic load-balances between them
- C.OSPF routes always override static routes regardless of AD; static routes are only used when no dynamic protocol runs
- D.Static routes have AD 255 (unreachable); they are only used as last resort when all dynamic routes fail
Why A is correct
Cisco administrative distances: Directly connected = 0, Static route = 1, EIGRP = 90, OSPF = 110, IS-IS = 115, RIP = 120, Unknown = 255. Lower AD wins. A static route (AD=1) is preferred over OSPF (AD=110) for the same prefix. A floating static route uses a higher AD (e.g., 200 or 250) so it only activates if the dynamic route is removed (used for backup WAN). Only one route per prefix is installed unless AD and metric are equal (ECMP). Option B is wrong (AD=0 is connected routes).
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