Networking in Software

Encoder UPC-A Supplement 5 in Software Networking

Networking
UPC-A Supplement 5 Scanner In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
Painting UPC Code In None
Using Barcode creation for Software Control to generate, create UPC-A image in Software applications.
internal network, or to other routers as appropriate. Having two network interfaces allows data to be passed through the machine and exchanged across different networks. In the preceding example, the company.com router was able to exchange information between the subsidiary.com router and the external router. Thus, many routers can be interconnected to form networks in which packets can be passed from a source to a destination host transparently. Since the subsidiary.com router serves as a packet-filtering firewall, it is likely that the network has a nonroutable internal structure that is not directly accessible to the external network but is visible from the router (the 10.17.65.0 network). Thus, a rogue user from company.com will be able to see the external interface for the subsidiary.com router but will not be able to see the internal interface, or any of the hosts beyond, unless she manages to break into the router through the external interface. This adds a second layer of protection against intrusion. A packet filter can then be used to explicitly deny connections to machines in the internal network, except for very specific system or network services. For example, a departmental mail server may reside on server1.subsidiary.com, and external machines will ultimately need access to the sendmail ports on this server. This can be achieved by port forwarding, the ability of the router to map a port on its external interface to a port on a machine on the internal network. For example, a Web server on server1.subsidiary.com:80 could be accessed from the external network by connecting to router.subsidiary.com:8080 if the mapping was enabled. These techniques can achieve the necessary logical isolation between external users and actual network configuration, which can be useful for security planning. Packet filtering, port forwarding, and nonroutable networks are discussed later in the chapter. A machine with more than one network interface may not be configured to act as a router, in which case it is referred to as a multihomed host. Multihoming can be useful for performing such functions as load balancing, and directly serving different class C networks without passing information between them.
UPC-A Recognizer In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
GTIN - 12 Printer In C#
Using Barcode creation for Visual Studio .NET Control to generate, create UPC-A Supplement 2 image in Visual Studio .NET applications.
IP Routing
UPC Code Printer In Visual Studio .NET
Using Barcode encoder for ASP.NET Control to generate, create UPC-A Supplement 5 image in ASP.NET applications.
UPC Symbol Maker In .NET Framework
Using Barcode maker for .NET Control to generate, create UPC Symbol image in .NET framework applications.
Now that you have reviewed how to install, configure, and tune network interfaces, this section describes how to set up routing, by explaining how packets are transferred from hosts to routers and exchanged between routers. This section also examines how to troubleshoot routing problems with traceroute, and introduces the different routing protocols that are currently being used on the Internet. There are two kinds of routing, static and dynamic. Static routing is common in simple networks with only a few hosts and networks interconnected. Static routing is much simpler to implement than dynamic routing, which is suitable for large networks, where the routes between networks cannot be readily specified. For example, if your organizational network has only 2 routers connecting three networks, then the number of routes that need to be installed statically is 4 (i.e., the square of the number of routers). In contrast, for a building with 5 routers, the number of routes that need to specified statically is 25. However, by using the default route facility, the number of routes to be specified drops significantly, as shown in the following example:
Printing GS1 - 12 In VB.NET
Using Barcode drawer for .NET Control to generate, create UPCA image in .NET framework applications.
Bar Code Generator In None
Using Barcode printer for Software Control to generate, create bar code image in Software applications.
23:
EAN 13 Creator In None
Using Barcode generator for Software Control to generate, create UPC - 13 image in Software applications.
Bar Code Creation In None
Using Barcode printer for Software Control to generate, create barcode image in Software applications.
Routing and Firewalls
Code 39 Encoder In None
Using Barcode creation for Software Control to generate, create Code 3 of 9 image in Software applications.
UCC - 12 Generation In None
Using Barcode maker for Software Control to generate, create EAN / UCC - 13 image in Software applications.
{data circuit}------R1---------R2------------R3-------{stub} R1 routes = default route to data circuit route to R2 and R3 (3 routes) R2 routes = default route to R1 & route to R3 (2 routes) R3 routes = default route to R2 (1 routes) Total routes = 3 + 2 + 1 = 6 If a router configuration changes, then all the static configuration files on all the routers need to be changed (i.e., there is no mechanism for the discovery of routes). Alternatively, if a router fails because of a hardware fault, then packets may not be able to be correctly routed. Dynamic routing solves all of these problems, but requires more processing overhead on each router. There are two related dynamic routing daemons in.rdisc, the router discovery daemon, and in.routed, the route daemon whose configuration will be discussed at length in this section.
USD-3 Creator In None
Using Barcode maker for Software Control to generate, create Code 93 Full ASCII image in Software applications.
Draw EAN / UCC - 13 In Objective-C
Using Barcode maker for iPad Control to generate, create EAN 13 image in iPad applications.
EAN / UCC - 13 Generator In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create UPC - 13 image in ASP.NET applications.
Barcode Recognizer In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
Printing UPC-A Supplement 2 In Java
Using Barcode generator for BIRT reports Control to generate, create UPC Code image in BIRT reports applications.
GS1 - 13 Creation In VB.NET
Using Barcode maker for Visual Studio .NET Control to generate, create EAN13 image in Visual Studio .NET applications.
Code 39 Drawer In Java
Using Barcode drawer for Android Control to generate, create Code 39 Full ASCII image in Android applications.
Bar Code Encoder In None
Using Barcode maker for Microsoft Excel Control to generate, create bar code image in Office Excel applications.
Copyright © OnBarcode.com . All rights reserved.