This document describes how to locate and troubleshoot the problems that cause website access failure.
Website access failure may be caused by network problems, firewall configurations or CVM overload.
CVM shutdown, hardware failure, and high CPU/memory/bandwidth usage may all cause website access failure. Thus, we recommend that you check CVM running status and CPU/memory/bandwidth usage.
The following operations take port 80, which is commonly used in HTTP service, as an example.
netstat -ntulp |grep 80command, as shown below:
netstat -ano|findstr :80command, as shown below:
iptables -vnLcommand to check whether iptables opens port 80.
iptables -I INPUT 5 -p tcp --dport 80 -j ACCEPTcommand to open it.
- If yes, please [troubleshoot network-related problems](#TroubleshootNetwork). - If no, please turn off the Windows firewall configuration.
Network problems can also cause network access failure. You can execute the following command to check whether the network has packet loss or high latency.
ping the public IP of the server
Security group is a virtual firewall that allows you to control the inbound and outbound traffic of the associated instance. You can specify protocols, ports and policies for security group rules. If you did not open the ports related to the Web processes, website access failure may occur.