Its primary focus is on data transfer using either TCP or UDP. Netperf: This is a perfect tool to measure the different aspects of a network’s performance. There are a few benchmarking tools available for networks, of which the following two can be the best choices. So, it is always advisable to benchmark every change you make, because any change that doesn’t result in an improvement is pointless and may degrade performance. But tuning without measurement (effected values) is useless as well as dangerous. To get maximum or even improved network performance, our goal is to increase the throughput (data transfer rate) and latency of our network’s receiving and sending capabilities. Figure 5: ss output Figure 6: netperf running as a server and client on the same system Benchmark before tuning Ss –l: This shows all the network ports currently opened. Ss: This is another helpful tool to see network statistics and works the same as netstat. It is used to display and change the settings of your network interface card.Įthtool eth0: This shows the hardware setting of the interface eth0. It has lots of statistics to show, and can be useful to find bottlenecks or problems.Įthtool: To tune your network, ethtool can be your best friend. Netstat:This utility shows all the network connections happening in your system. Other options and usage can be seen in man ip. Ip link or ip addr: This gives detailed information of all the interfaces. It is used to set up and control the network. Ip: This tool shows/manipulates routing, devices, policy routing and tunnels (as mentioned in the man pages). Figure 4: The entire Net adapter details shown by ethtool eth0 Tools to monitor and diagnose your system’s network This is handled by the NAPI (new API), which makes the processing of incoming packets more efficient by putting the device driver in polling mode. Note: Initially, a hard interrupt is raised by the device driver to send data to the kernel, but since this is an expensive task, it is replaced by a software interrupt. The data then gets copied to the preferred data receiving process. ![]() ![]() When all the packets are filled in the kernel buffer, they get sent to the upper processing layer – IP, TCP or UDP. ![]() The packet data in the Linux kernel gets stored in the sk_buff data structure to hold the packet up to MTU (maximum transfer unit). Once the packet is accessible to the kernel, the device driver raises softirq (software interrupt), which makes the DMA (data memory access) of the system send that packet to the Linux kernel. This article covers network performance monitoring and tuning methods-mostly parameters and settings available in the OS and network interface card (NIC)-that can be tweaked to improve the performance of your overall network.įigure 1: Data receiving process Figure 2: ip addr output for loopback and eth0 interface Figure 3: netstat-ta shows all the tcp connections happening in the system How your operating system deals with dataĭata destined to a particular system is first received by the NIC and is stored in the ring buffer of the reception (RX) present in the NIC, which also has TX (for data transmission). That is why, to get the most out of your fast Ethernet cable, as well as high bandwidth support and a high data transmission rate, it is important to tune your operating system. Your organisation can spend money to buy high quality Ethernet cables or other networking devices to send terabytes or petabytes of data but may not experience performance improvements because, ultimately, the data has to be dealt with by the operating-system kernel. But our microprocessors lag behind when it comes to processing the data received and transferring it through them. The improvement in the performance of networking devices like switches, routers and connectors such as Ethernet cables has been huge in recent years. If you are a victim of poorly performing network devices, this article may help you to at least alleviate, if not solve, your problem. There’s nothing more annoying than a slow network connection.
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