To solve the problem of abnormal login displayed on a cloud server, follow these steps:
Check Login Credentials: Ensure the username and password (or SSH key) are correct. For example, if using SSH, verify the key is added to the authorized_keys file.
Review Server Logs: Examine system logs like /var/log/auth.log (Linux) or Event Viewer (Windows) for authentication errors. Look for failed login attempts or IP blocks.
Firewall and Security Groups: Confirm the server’s firewall (e.g., iptables, ufw) or cloud security groups allow traffic on the login port (e.g., port 22 for SSH, port 3389 for RDP).
Account Status: Verify if the user account is locked or expired. On Linux, use passwd -S <username> to check account status.
IP Restrictions: If login is restricted by IP (e.g., via /etc/hosts.allow or cloud security policies), ensure your current IP is whitelisted.
Brute Force Attacks: If logs show repeated failed attempts, the server may be under attack. Use tools like fail2ban (Linux) to block malicious IPs.
Reboot or Reset: If the issue persists, restart the server or reset the login service (e.g., systemctl restart sshd).
For enhanced security and monitoring, consider using Tencent Cloud’s Cloud Monitor to track login activities and Tencent Cloud Security Center to detect and mitigate threats. If the server runs on Tencent Cloud, leverage VPC network ACLs and CVM security groups to manage access rules efficiently.