NetGuido

Until now, Unix and Linux distributions have retained the “venerable” commands arp, ifconfig and road as tools for configuring network interfaces. Given the developments listed above, it became very difficult to complete or adapt this legacy. That is why the network architecture kernels 2.4.xx has been completely redesigned to make different levels of configuration interfaces more accessible. This new architecture involves the establishment of a new configuration tool: iproute2.


IP The command ip is used to configure the interfaces. The syntax of this command is provided in the documentation of the iproute package as well as in the guide Linux Advanced & Traffic Control HOWTO. The options of this command settings include:
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interfaces at the liaison and networking,
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addresses according to the protocols,
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entries routing table,
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entries in the database routing policies,
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addresses and tables broadcast (multicast)
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tunnels.
tc
The command tc: (Traffic Control) is used to set up traffic control to interconnect. It uses the following elements:
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a choice of managers queuing a network stream,
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a choice of classification rules packages before putting them in the queue,
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a choice of schedulers for formatting traffic leaving one interface.
5.2. Policy routing
All treatments made with the association orders and ip tc is called policy routing or routing policy. The Linux kernel has a database management system routing: DPSP or Routing Policy DataBase management. This database is working on the following fields:
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MAC addresses source and destination,
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IP addresses source and destination,
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the type of Service: TOS,
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interface arrival of the package.
In addition, treatment protocols level of transport may be associated with the filtering system services. Depending on all these parameters, there are four treatments or policing possible for a package arriving on an interface:
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making a filter,
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refusal of queuing,
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abandonment of a package in the queue,
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abandonment of a package to queue at the arrival of a new package.
All of these mechanisms can refine treatment flow network. Once the first stage of differentiation between flows past, we can tailor treatments: priorities. Thus, we can assure multimedia services (data, audio, video) over heterogeneous networks.
5.3. Extensions Diffserv
The differentiated services or Differentiated Services, or Diffserv correspond to a simple classification of traffic entering a network or conditioning at the border of the interconnection network referred.
The traffic condition is identified by a field DS or marking of the field Type of Service (ToS) from the header of IP packet. One of the basic principles of the technique Diffserv wants marking traffic takes place on the equipment ends of the network. Knowing that this work of marking is quite complex and costly in time of calculation, it is better to minimize repetition. It is therefore on the end routers that the marking should be done to ensure that devices inside the network no longer have to apply classes of service CoS on flows identified.
The application of differentiated services on components existing traffic control Linux kernel that has resulted in additions minors on these components. As the mechanisms for classifying network flows are complete, it is virtually lacking that support and the necessary elements to manipulate the field DS. The site Differentiated Services on Linux brings together all the information necessary for the implementation of Diffserv on GNU / Linux systems.
Trade flows marked through Internet
Trade flows marked through the Internet - complete overview
The article Linux and the Next Generation Internet describes a sample configuration of this type.