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Figure 27.1 |
(a) An architecture where static routing is used, and (b) a static routing table used in a host. |
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Figure 27.2 |
Three networks connected by two routers. In such situations, dynamic routing can be used to propagate information about remote networks. |
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Figure 27.3 |
The Internet routing architecture. Each autonomous system chooses an IGP to use internally; an EGP is used to communicate between autonomous systems. |
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Figure 27.4 |
The flow of routes and data illustrated with ISPs. After a router in ISP1 advertises routes to customers, data can arrive for those customers. |
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Figure 27.5 |
The format of a RIP version 2 update message. The message contains a list of destinations and a distance to each. RIP measures distance in hops. |
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Figure 27.6 |
(a) An internet consisting of seven networks interconnected by routers, and (b) a corresponding OSPF graph. In the simplest case, each router corresponds to a node in the graph. |
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Figure 13.4 |
(a) A network consisting of three packet switches, and (b) the next-hop forwarding information found in switch 2. Each switch has different next-hop information. |
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Figure 13.5 |
An abbreviated version of the routing table in Figure 13.4b made possible by hierarchical addressing. When forwarding to a local computer, the switch uses the second part of the address to select a specific computer. |
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Figure 13.7 |
The routing table for each node in the graph of Figure 13.6. The next-hop field in an entry contains a pair (u,v) to denote the edge in the graph from node u to node v. |
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Figure 13.8 |
Revised version of the routing tables in Figure 13.7. An asterisk in the column labeled destination denotes a default route. |
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Figure 13.9 |
A graph with weights assigned to edges. The shortest path between nodes 4 and 5 is shown darkened. The distance along the path is 19, the sum of the weights on the edges. |
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Figure 20.2 |
(a) An example internet with three routers connecting four physical networks, and (b) the conceptual routing table found in router R2. Each entry in the table lists a destination network and the next hop along a route to that network. |
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Figure 20.3 |
(a) An internet of four networks and three routers with an IP address assigned to each router interface, and (b) the routing table found in the center router. Each entry in the table lists a destination, a mask, and the next hop used to reach the destination. |
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Animation 16_1 |
Hosts and routers consult routing tables to forward IP datagrams. Each host or router looks in its routing table to determine the next hop to the destination. If the routing tables are changed, IP datagrams will follow different paths to the destination. |
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Photo 7_007 |
Cisco 15900 Wavelength Router, which uses DWDM (dense wave-division multiplexing). |
