Static Routing

Static Routing > Exam relevance: Static routing sits inside IP Connectivity (25% of the exam) and appears in both multiple-choice questions and simulation tasks. You must be able to configure, verify, and troubleshoot all four static route types cold. --- ## Why Routers Need Routes A router can only forward a packet if it has an entry in its routing table that matches the destination. Routes are learned three ways: directly connected networks (automatic), static routes (manually configured by an admin), and dynamic routing protocols (like OSPF). Static routes give you precise, predictable control but require manual maintenance as the network changes. --- ## The Routing Table — Context First Before configuring static routes, understand how the router selects among competing entries: | Code | Meaning | Default AD | |------|---------|-----------| | C | Connected | 0 | | L | Local (interface IP/32) | 0 | | S | Static | 1 | | O | OSPF | 110 | Administrative Distance (AD) is the router's trust ranking. Lower AD wins when two sources advertise the same prefix. A static route (AD 1) beats OSPF (AD 110) — which is exactly how floating static routes work (more below). --- ## The Four Static Route Types ### 1. Network Static Route Used to reach a specific remote subnet. Syntax: `` ip route [destination-network] [subnet-mask] [next-hop-IP | exit-interface] ` Example scenario: Router R1 needs to reach the 192.168.30.0/24 subnet. The next-hop router's IP is 10.0.0.2. ` R1(config)# ip route 192.168.30.0 255.255.255.0 10.0.0.2 ` After this, show ip route will show: ` S 192.168.30.0/24 [1/0] via 10.0.0.2 `` ### 2. Default Static Route (Gateway of Last Resort) Matches any destination when…