| 9.1 |  | Examining the Routing Table |
| 9.1.3 |  | Determining route source and destination |

| For traffic going through a network cloud, path determination occurs at the network layer. The path determination function enables a router to evaluate the available paths to a destination and to establish the preferred handling of a packet. Routing services use network topology information when evaluating network paths. This information can be configured by the network administrator or collected through dynamic processes running in the network. The network layer provides best-effort, end-to-end, packet delivery across interconnected networks. The network layer uses the IP routing table to send packets from the source network to the destination network. After the router determines which path to use, it takes the packet from one interface and forwards it to another interface or port that reflects the best path to the packet's destination.
| Web Links Using the Extended ping and Extended
traceroute Commands http://www.cisco.com/en/US/tech/ tk826/tk365/ technologies_ tech_ note09186a0080093f22.shtml