Sts

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 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.

Dynamic Routing 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 Function

Static

Dynamic

Routing Tables

Manually created and maintained

Dynamically built

Sharing Information

Does not share information

Share information among routers

Route Discovery

Function of IP

Function of Routing protocol(e.g.,RIP)

Internetwork

Small

Large

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.