IP
IP Routing
6-19
The entire security table can be cleared with the following command.
Figure 6-43:
Clearing the Security Table
6.7 IP Routing
TCP/IP internets are usually broken down into networks. Each host on a particular network can only see
hosts on its network; to transfer network traffic to other networks, routers (also called gateways) are
required. Routers are typically connected to two or more networks.
The SCS serves as a router for the networks that it is directly connected to. To determine the path to other
routers on the network, the SCS will listen to network broadcast packets (for example, RIP packets); routers
will advertise themselves in these packets.
The SCS must be positioned between two networks in order for routing to work correctly. If two or more
SCSs are used, the units cannot be on the same network (as in Figure 6-44).
Figure 6-44:
Two Units Used to Link the Same Network
6.7.1 How Packets are Routed
When an IP host tries to send a packet, it looks to see if the destination address is on the same network as
the host’s IP address. If it is, the host sends the packet directly to its destination. If the packet is destined for
a different network, the host sends it to a router (in this case, the SCS).
When the SCS receives the packet, it examines the packet’s destination address, determines the most
efficient route to this address, and forwards the packet to this location. The “most efficient route” is
determined using two factors: the network that the address is part of and the SCS routing table, which is
discussed in the following section.
6.7.2 Routing Tables
The SCS uses a routing table to keep track of which networks are reachable, and the shortest route to each
network. A typical routing table entry consists of the destination network, and which router is the best path
to that network. Routing tables also keep track of the cost or metric required to get to a given network.
6.7.2.1 Types of Routes
There are three types of routes: host, network, and default.
Local>> CLEAR IP SECURITY ALL
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Summary of Contents for SCS
Page 14: ...xii ...
Page 171: ...Modem Sharing Examples 10 6 ...
Page 314: ...Command Reference Service Commands 12 110 ...
Page 403: ...Show 802 11 Errors Rightmost Number B 5 00000002 Internal error 00000001 Internal error ...
Page 424: ...Index 13 ...