What does isp mean? global networks

Many people ask how the provider's network is arranged or how they can build the network themselves, in this article I will show how the network is designed and works for me, at the logical level. Although I don’t consider my structure to be ideal, it could have been done better, but this is my IMHO :) for the truth is “ask 2 providers how to build a network - you will get 3 different options”

Now more about how it works

A typical data network consists of 4 layers, many say that 3 but in fact there are 4

Level 1 - the border of the network, i.e. the junction with other operators, it is also a border
At this level, we usually work with backbone operators from whom we take the Internet and operators with clients - to whom we give the Internet :) Interaction in 90% of cases is carried out using the BGP dynamic routing protocol

Level 2 is the very core of the network
It includes billing, a radius server, central switches where everything is plugged in, NAT and shapers (with which we cut the band to the client. You can also cut it on the port of a managed switch - but in this case, local resources will be at a tariff rate, we also need to provide a tariff rate to the Internet and up to 100 Mbps within your network
Communication between equipment usually also occurs using dynamic routing protocols such as BGP (In this case, internal BGP or OSPF), but there are also adherents of static routes

Level 3 is the level of distribution, aggregation
This layer usually usually includes managed switches (2nd or 3rd layer) of a block or district, depending on the internal structure of the network. In my case, level 3 switches are installed and sometimes supplemented with a level 2 switch, because with the VLAN scheme for the house, you should not rake up the house vlans in the network core 

Level 4 - access level, access, client access point
These are the same house switches that are in the basements and attics of houses in a box. Clients are already connected to them. In the CIS countries, D-Link DES-3526, D-Link 3026 are most often used and they slowly began to install D-Link DES-3028, for legal entities they usually disdain long lines and install Cisco Catalyst 2950

Now about how it works for me:

1) Level 1 device

As border routers, 2 Juniper j4350 pieces of iron are used, each of which has its own backbone uplink, interaction with uplinks occurs using the BGP protocol (i.e. we give the uplinks networks assigned to our AS (autonomous system) and get from them a complete list of routes in the network Internet (full view)

2) Level 2 device

At the second level, NAT-ing of clients, shaping of tariff rates and routing (Internet or peer-to-peer networks)

Two Intel server platforms running FreeBSD are used as NAT-ers and shapers (each of them performs both NAT and speed slicing, and each of them reserves each other). Shaping is done with dummynet and tables (tablearg) and nat with pf
Also, internal BGP runs between these routers and border routers (j4350) so that in case of failure of one of the borders, it will quickly switch to the second and some kind of traffic balancing will also not be superfluous 
Between routers and switches of the 3rd level, the OSPF protocol runs to exchange intranet and peer-to-peer routes + we announce the default route from routers to them, i.e. the default route. Router 1 has a metric of 100
Router 2 has a metric of 200, i.e. if one of the routers fails, all packets will go through the backup ones (the switching interval is about 10 seconds)

3) Level 3 device

With my VLAN scheme for the house, at the distribution level, I have to keep layer 3 switches that route home networks and vlans.
IGMP snooping works on the switches, all unnecessary multicast is cut off and broadcasts and NetBIOS ports are cut (tcp / udp 135-139, 445)

4) Level 4 device

At the fourth level there are D-Link DES-3526 switches, we plan to install DES-3028, because 4 gigabit ports are very often needed. Yes, and according to rumors, 3526 is already EOL
Clients connect directly to the switches, loopback detect is enabled on subscriber ports (to turn off ports with a loop), the maximum number of mac-addresses per port is 5, igmp snooping is enabled and all multicast is filtered except for the ranges 224.200.100.0-224.200.150.255 and 224.0.0.2 , all broadcasts are also killed (except for the arp protocol) and the entire NetBIOS

Services module

Viewing a List of Services

• Name- name of the service.
• State- Graphic indicator of service activity and automatic restart.

Service start

To start a service, select it in the list and click the "Start" button in the toolbar. To prevent accidental actions, the control panel will ask you to confirm or cancel your action. If you click "OK" in the confirmation window, the selected service will be started.

Stopping the service

To stop a service, select it in the list and click the Stop button on the toolbar. To prevent accidental actions, the control panel will ask you to confirm or cancel your action. If you click "OK" in the confirmation window, the selected service will be stopped.

Service restart

To restart a service, select it in the list and click the "Restart" button in the toolbar. To prevent accidental actions, the control panel will ask you to confirm or cancel your action. If you click "OK" in the confirmation window, the selected service will be restarted.

Add service to autostart

If you want the service to automatically start after the system reboot, select it in the list and click the "On" button. To prevent accidental actions, the control panel will ask you to confirm or cancel your action. If you click "OK" in the confirmation window, the selected service will be added to autostart.

Remove service from autostart

If you want to remove a service from autostart, select it in the list and click the "Off" button. To prevent accidental actions, the control panel will ask you to confirm or cancel your action. If you click "OK" in the confirmation window, the selected service will be removed from autostart.

Add a service to monitoring

To monitor the health of a service, select it in the list and click the "Add" button.

• Service name- service name defined in the system.

• Process name- the name of the process to control the monitoring of the service, if this parameter was defined in the list of displayed services, then this value will be loaded automatically.

• Service type- defines the way to monitor the state of the service (see Monitoring operation).

• Set your own parameters- the presence of this flag means that the user must independently specify the IP address and Port on which the service is running.

• IP address- The IP address where the service is running.

• Port number- the port on which the service is running.

Service settings module

Remove a service from monitoring

To remove a service from monitoring, select it in the list and click the "Delete" button. To prevent accidental actions, the control panel will ask you to confirm or cancel your action. If you click "OK" in the confirmation window, the selected service will be removed from monitoring.

November 6th, 2013

In this post, I will outline the problem with Sagemcom 2804 v7 that our colleagues from the Krasnoyarsk branch of Rostelecom faced. They kindly shared the solution to the problem, the essence of which is as follows:
The router is authorized in the provider's network, but with all this, there is no Internet on the connected devices. If you go to the connection status page in the web interface of the router, you will see the line "Waiting for ISP". Why is this happening and how to deal with it?!
The thing is that for Sagemcom 2804 v7 there is such a firmware version, in which, when setting up PPPoE, in the Routing - default gateway selection and DNS server configuration sections, usb0 is used instead of the ppp1 interface.

Of course, if the user leaves everything like that when setting up the connection, then nothing will work.
The solution is simple - you need to reconnect. Then, when configuring the default gateway on the Sagemcom 2804 v7, you just need to throw usb0 with an arrow to “available routable wan interfaces” and ppp1, respectively, to throw it to “selected default gateway interfaces”:

The same must be done in the DNS Server Configuration section:

P.S. Many thanks to the employees of the Krasnoyarsk branch of Rostelecom, in particular to Sergey Golovko.

Characteristics of ISP networks.

Purpose of ISP networks.

Networks are divided into two main types - local area networks (LAN) and global or distributed (WAN).

Internet Service Provider (ISP) networks are global networks. At the same time, according to the technologies used and the tasks to be solved, ISP networks are compatible with corporate networks. That allows you to consider ISP networks from the point of view of building corporate networks. Since the resources of such networks are distributed over vast geographical areas, such networks are called distributed.

In the global network, information is exchanged between geographically remote areas. To ensure the exchange of information between two remote workstations, WAN links are used.

The exchange of information of a certain type in the WAN is called a service or service.

The ideal ISP network should support services such as:

• Voice over IP (Voice over IP);
• Video transmission (video conferencing).
• Data transfer
• Business applications and services.

The main tasks of the ISP network are:

• Provision of access services to remote services and information resources to individuals and companies;

• Creation of a single information space for distributed offices of companies;
• Support for corporate applications and services.

The ISP network is a complex system consisting of various media and data transmission technologies. A variety of protocols are required to make such a network work.

Modern backbone and edge switches can support WAN technologies such as ATM, Frame Relay, MPLS. This allows you to combine networks of different types and reduce the cost of providing services using a small set of telecommunication devices.

Modern network equipment makes it possible to implement the technology of new generation IP multiservice networks, which widely support traffic separation by Quality of Service (QoS). This enables the introduction of new voice-over-IP and video-on-demand services. As a result, a single network infrastructure is created for voice, data and video transmission based on IP using ATM/FR (frame relay), Internet, IP VPN and Ethernet.

The efficiency of equipment and the expansion of the capabilities of data transmission media are constantly increasing, but at the same time, the design of distributed networks is becoming more difficult. The detailed design of a distributed network reduces the problems associated with their growth.

ISP network requirements:

· Multi-service – support for various types of traffic (transmission of data, voice, video, service information and protocols.

· Convergence - minimizing the time to update routing information.

• Reliability of information transfer;
• Transmission security;
• Scalability of the network and services provided;
• Manageability of the corporate network.
• Ability to use new services and applications.

When developing a corporate network or an ISP network, you need to solve the following tasks:

· Regulation of the requirements for the network and the tasks solved by the network.

· Network structure and data transmission technology.

· Choice of network equipment.

Nodes can connect to ISP(Internet Service Provider) and the Internet in several ways.

Obtaining a public or private address depends on the host connection method.

Direct connection

Some customers have only one computer with a direct modem connection to their ISP. In this case, the public address from the ISP's DHCP server is assigned to only one host.

Connection via integrated router

If you need to connect more than one site to the Internet, you can connect your ISP modem not to a single computer, but directly to an integrated router. This creates a home network or a small business network. The integrated router receives public addresses from the ISP. Internal hosts receive private addresses from the router.

Connection via gateway

Gateways combine an integrated router and modem and connect directly to an ISP. As with integrated routers, the gateway receives a public address from the ISP, while PCs on the internal network receive private addresses from the gateway.