Azure VM单IP请求超限后限制访问的方案咨询

Absolutely, Azure has several built-in tools to tackle this exact scenario—let’s break down the most straightforward and effective solutions you can implement directly from the Azure portal, plus a few extra layers to prevent recurrence.

This is the fastest way to shut down that problematic IP. NSGs act as a firewall for your VM's network interface or subnet, letting you block specific traffic at the network level:

• Head to your VM in the Azure portal, navigate to the Networking tab.
• Click the associated NSG (if you don’t have one linked yet, create a new NSG and attach it to your VM’s NIC or subnet first).
• Go to Inbound security rules and click Add.
• Set a high-priority rule (use a low number like 100—rules are evaluated in order of priority, lower numbers first). For Source, select IP Address and input the malicious IP. Choose the relevant Destination ports (e.g., 80/443 for web traffic), set Action to Deny, then save.
• Pro tip: If you notice multiple suspicious IPs, you can block entire ranges here too, but for a single bad actor, direct IP blocking is perfect.

If you’re managing multiple VMs or need more advanced controls, Azure Firewall is your go-to. It lets you set rate limits and block IPs across your entire environment:

• Configure a Network Rule to deny traffic from the target IP to your VM’s web ports.
• For more granular control, use Application Rules to set rate limits on HTTP/HTTPS requests (e.g., cap requests from a single IP to 100 per minute).
• The best part? You can centralize all your traffic policies here, and integrate with Azure Monitor to log and analyze blocked requests.

Don’t overlook the web server itself—adding rate limits directly on your VM’s web service adds a second layer of defense:

• IIS: Use the Dynamic IP Restrictions module to set a maximum request count per IP (e.g., 100 requests/minute). You can configure it to block the IP temporarily or permanently once the threshold is hit.
• Nginx: Add rate limiting directives to your config file. Example:

  limit_req_zone $binary_remote_addr zone=web_limit:10m rate=100r/m;
  server {
      location / {
          limit_req zone=web_limit burst=10;
      }
  }
  

• Apache: Use modules like mod_ratelimit or mod_reqtimeout to restrict how often a single IP can send requests.

If this traffic qualifies as a targeted DDoS attack (even from a single IP), Azure DDoS Protection Standard automatically detects and mitigates it:

• Enable it on your VM’s virtual network. It monitors traffic patterns and triggers mitigation when traffic exceeds normal thresholds—this includes blocking excessive requests from a single IP.
• It also provides detailed attack reports so you can analyze the scope and adjust your defenses further.

Before blocking anything, confirm the IP is indeed malicious:

• Use Azure Monitor to pull network traffic logs for your VM, cross-checking request counts and source IPs.
• Set up an Azure Alert to notify you immediately when an IP exceeds your request threshold (e.g., 100 requests/minute)—this way you can respond fast next time.

内容的提问来源于stack exchange，提问作者IT Team