150 likes | 178 Views
Static Routing Technique. What is Routing. the act of moving information across an internetwork from a source to a destination Bridge the mid-1980s. Routing Components. Path Determination Switching. Routing Algorithms. Design Goal Optimality Simplicity and low overhead
E N D
What is Routing • the act of moving information across an internetwork from a source to a destination • Bridge • the mid-1980s
Routing Components • Path Determination • Switching
Routing Algorithms • Design Goal • Optimality • Simplicity and low overhead • Robustness and stability • Rapid convergence • Flexibility
Routing Algorithms • Algorithm Types • Static Versus Dynamic • Single-Path Versus Multipath • Flat Versus Hierarchical • Host-Intelligent Versus Router-Intelligent • Intradomain Versus Interdomain • Link-State Versus Distance Vector • Routing Metrics
Routing Metrics • Path length • Reliability • Delay • Bandwidth • Load • Communication cost
Static Routing • manually configure routers by administrator • Entrys in the routing table may be a destination. • paths are unchangeable.
DynamicRouting • routing algorithms • discover changes, automatically adjust routing tables, and inform other routers. • some paths may be manually configured to control the routing environment.
Static vs Dynamic Ps. Most routers support both static and dynamic routing.
Static Routing in Linux and IOS • Most dynamic routing • static routing to configure their default route • routers run a routing protocol that automatically updates routing tables • Static routing entries can be added, even if a router runs a routing protocol, however, static routes may interfere with the path calculation determined by a routing protocol. • configuration file
Static Routing in Linux and IOS(2) • routing cache. • a separate entry for each destination IP address. • delete if it has not been used for some time.
Routing Protocol • Routing Information Protocol (RIP) • Hello • Open Shortest Path First (OSPF)
Debugging static routing configurations • Tools and Utilities • Ethereal • Ping • Traceroute • netstat –rn • Show ip route
Debugging static routing configurations(2) • Example • ping: find unsuccessful connections • traceroute: find the last successful router • netstat –rn / show ip route: determine which routing table entry is incorrect or missing.