There are myriad reasons behind faulty network performance. Network problems can arise from faulty hardware such as routers, switches, and firewalls. They can also arise from unexpected usage patterns such as in the case of network bandwidth spikes that exceed their allocated bandwidth for users, or due to security breaches, changes in device configuration, etc. Let’s explore seven key network performance issues that commonly and persistently impact enterprise networks.
#1 High CPU Utilization – The most common cause of high CPU utilization is when your network is bogged down by enormous network traffic. CPU utilization increases when processes need more time to execute or when more network packets are sent and received. For instance, if a switch or a router fails to respond or performs processes very slowly, it’s usually due to high CPU utilization.
#2 Route Flapping – Any misconfiguration on the router, hardware failure, or a loop in the network can cause route flapping. This is noted as an instability in the routing table where the existence of the route is on and off, which in turn advertises alternate routes, frequently.
#3 High Network Errors and Discards – Errors indicate packets that were received unprocessed because there was a problem with the packet. The reasons can be misconfiguration on one end or a bad cable on the other, etc. But with Discards, the packets are received with no errors but were dumped before being passed on to a higher layer protocol. Normally, the root cause of discards is when the router wants to recover some buffer space.
#4 Network Access Link Congestion – If your sales (VoIP) calls are dropping, it means there’s a network access link congestion. This is a bottleneck between a high bandwidth LAN and a high bandwidth IP network. An increase in traffic can cause the queue in router to fill, which increases jitter and causes a short term increase in time delay. High levels of jitter cause excessive numbers of packets to be discarded by the receiving VoIP system, which leads to degraded voice quality.
#5 Network Link Failure – A link failure typically appears as a period of consecutive packet loss that lasts for many seconds, followed by a change in delay after the link is re-established. But, routers are capable enough to find alternate routes if they find a link failure. Regular occurrence of packet loss/link failure could be a symptom of equipment or power supply reliability problems.
#6 Misconfigured Hardware or Software –The negative effects of misconfiguration may result from a LAN being oversubscribed or overloaded, but most often they result from overlooked configurations. For instance, a segment (VLAN) can be easily overloaded by multicast traffic, if multicast traffic constraining techniques are not properly configured on that VLAN. Such multicast traffic may affect the data transfer rate of all the users in the network.
#7 Packet Loss – In some cases, a network is considered slow when applications require extended time to complete an operation that usually runs faster. That slowness is caused by the loss of some packets on the network, which causes higher-level protocols like TCP to time out and initiate retransmission.
How to find and mitigate these network issues?
Using network fault and availability monitoring software will help you to simplify detection, diagnosis, and resolution of network issues before outages occur. This will help you to mitigate all the above issues discussed with ease. If you need more information on how to choose a network and bandwidth monitoring tool, you can check out this guide.