How do low-end and high-end routers affect network security?

"Low-end routers and high-end routers are similar in usage. Why is the price so far different ?" In fact, this question is very good, and many friends who are not familiar with the product and technology will basically have similar questions-"Why is this router so expensive with the same functions, another one is so cheap. "Why is Cisco's vro so expensive? And TP-LINK is so cheap ?" "The two routers have the same main parameters. Why is the performance so far different ?"

For these problems, we must start with the basic principles of routers.

How routers work

The simplest network can be imagined as a single-line bus. Each computer can send packets to the bus to communicate with each other. However, as the number of computers in the network increases, this is not feasible and may cause many problems:

1. bandwidth resources are exhausted.

2. Each computer wastes a lot of time processing unrelated broadcast data.

3. The network becomes unmanageable, and any errors may paralyze the entire network.

4. Each computer can listen to communications from other computers.

Network segments can solve these problems, but at the same time, you must provide a mechanism for computers in different network segments to communicate with each other, that is, to promote devices such as routers:

The router works at the IP network layer to forward data between subnets. Vrouters generally have multiple network interfaces, including local network interfaces and wide area network interfaces. Each network interface connects to a different network. The router records the network information connected to each network port. At the same time, a route table is stored in the router, which records the port numbers to be sent to different network addresses. The communication information of various information services used by Internet users can all be attributed to information transmission in units of IP packets. In addition to the data information to be transmitted, it also contains the destination IP address to be sent, the source IP address to be sent, and some related control information. When a router receives an IP packet, it searches for the route table based on the destination IP address in the packet and sends the IP packet to the corresponding port based on the search result. The next IP router continues forwarding after receiving the packet until it is sent to the destination. Routers can exchange route information through the routing protocol to update the route table.

Factors Affecting vro Performance

After the above introduction, we may not know much about the work of the router, but it doesn't matter. This is not our purpose. We mainly want to explain it to you, the working principle of the router determines that it must use a chip to complete some necessary judgment and data packet forwarding, which is done by a processor, various data packets to be processed or processed exist in the memory. Therefore, the operating frequency and memory capacity of the processor determine the performance of a vro to a large extent.

However, the performance of the vro cannot fully depend on the processor frequency and memory capacity. However, the performance of the vro is poor, but the performance of the vro is not necessarily good; the processor clock speed is only a performance indicator of the processor. Its bus width (16-bit or 32-bit), Cache capacity and structure, internal bus structure, single CPU, multi-CPU distributed processing, computing mode, and other indicators will affect the performance of the processor. Almost all routers use a communications-related CPU. Therefore, "using a communications-related CPU" is equivalent to saying nothing. The key lies in what kernel is used by the CPU and the internal structure. The same is true for the memory. The size of the memory does not matter. If the load is not large, there may not be much difference between the 4 M memory and the 8 M memory, therefore, it is not scientific to judge vro performance based on the memory size (of course, the large memory capacity is still advantageous ).

Indicators that determine the router grade

Although it has already been said that the processor and memory determine the performance of the vro to a large extent, however, the indicators that determine the grade of a vro are not them, this is why the two parameters are often not marked in the main parameters of the product. What is used to measure the grade of a router? The load capacity is also called the number of hosts. However, the number of bring-in devices is not a standardized data volume. It must be measured based on actual usage. For example, all people in Internet cafes are immersed in online chat and games, in addition, almost all data is transmitted through the WAN port of the router, so the load is very heavy. However, if it is a corporate network, most people are busy designing, writing reports, and making plans, at the same time, only a small number of people are using the network, and most of the data is flowing inside the enterprise network, so the router load is very light, then you can load more clients at the same time. If the maximum load is 253, it makes no sense, because the maximum number of IP addresses that DHCP can allocate is 254, and the number of IP addresses that DHCP can use is 253, this kind of metric cannot be called. It is basically a hit person. Therefore, we need to look at the actual load capacity of a router, rather than the theoretical load capacity.

Because of the many uncertainties and spoofing nature of the load capacity, another indicator is also quite concerned, that is, throughput. Throughput refers to the amount of data that the router can process per second. This parameter refers to the throughput of the LAN-to-WAN. The measurement result is that when NAT is enabled and the firewall is disabled, use the Smartbits and Chariot test methods respectively. When using the Smartbits method, compare the 64-byte packet test data and determine whether to compete. The Chariot test is best performed under multiple connections. Generally, you can select 100 pairs for the connection to see the differences between products.

Causes of router price impact

After the above discussion, we can finally return to the question we want to answer: Why is the price difference between different routers so big?

Main reasons:

1. vrouters with different performance have powerful built-in processor and large memory capacity, so the cost is relatively high.

2. different applications, vrouters with strong performance can be used for networks with more loads, while low-end vrouters cannot.

3. different functions. Although the basic functions are the same, some routers also have other practical functions, such as professional firewall functions and VPN functions. Therefore, they have high technical requirements, the price will naturally increase.

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