Routers, firewalls and switches process large amounts of network data by the minute. By economies of scale, the larger the network, the larger the volumes and types of data flowing through it will be. Monitoring the performance of networking devices is a must for network engineers to provide optimal uptime and peak performance to the business. If your networking devices are suffering from issues like high CPU (Central Processing Unit) usage, it can cause some serious network performance issues.
This week we look at causes of high CPU usage and what you can do to eliminate them. There are a number of things that can cause your networking hardware to experience performance issues and they can sometimes be traced to configuration settings.
Here are a few causes of high CPU usage on networking devices:
Legacy hardware: Newer routing and switching hardware comes with additional performance and security features that push networks to new limits. Older equipment with slower CPUs can create bottlenecks in your network and if you’re not in the market for an upgrade project, look into the configuration of your devices and evaluate their effects in terms of processing overhead.
Access control lists: Access control lists (ACL) add an additional layer of security to networks, but configuring too many ACLs on your devices might cause high CPU usage with a negative effect on performance. ACLs are known to cause processing overhead in routers, especially if they are configured with multiple lists of varying complexities.
Encryption: If your router is already subjected to high CPU usage, then you should consider the effects of enabling encryption. Conduct thorough before and after testing scenarios on encryption before enabling it on your devices.
Data compression: Although data compression can have some great results for network performance, you should once again consider the impact on your internal hardware when delving into compression scenarios. Software compression is known to take large percentages of CPU usage and with routers supporting various other functions, can become overloaded and cause network latency. Pre-compressed data can cause performance issues on routers when additional compression attempts are made on already compressed data packets.
Consider the implications of high CPU usage for your devices carefully.
Testing environments are ideal for assessing the efficacy of configuration changes intended for the live environment. Any negative impacts can be assessed and rectified before going live. Although additional security and performance levers, such as compression and encryption, can be pulled on routers and switches, it is important to fully understand their implications for your device resources and overall network performance. Orchestrating a large scale network can be tedious and requires patience when testing new configurations aimed at optimising network performance.