- What's New
- Function Overview
- Service Overview
- Billing
- Getting Started
-
User Guide
- Creating a User Group and Granting Permissions
- Checking the Dashboard
- Purchasing and Changing the Specifications of CFW
- Enabling Internet Border Traffic Protection
- Enabling VPC Border Traffic Protection
- Enabling NAT Gateway Traffic Protection
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Configuring Access Control Policies to Control Traffic
- Access Control Policy Overview
- Configuring Protection Rules to Block or Allow Traffic
- Adding Blacklist or Whitelist Items to Block or Allow Traffic
- Viewing Protection Information Using the Policy Assistant
- Managing Access Control Policies
- Managing IP Address Groups
- Domain Name Management
- Service Group Management
- Attack Defense
- Viewing Traffic Statistics
- Viewing CFW Protection Logs
- System Management
- Permissions Management
- Using Cloud Eye to Monitor CFW
- CTS Auditing
-
Best Practices
- CFW Best Practice Summary
- Purchasing and Querying CFW via API
- Migrating Security Policies to CFW in Batches
- Configuration Suggestions for Using CFW with WAF, Advanced Anti-DDoS, and CDN
- Allowing Internet Traffic Only to a Specified Port
- Allowing Outbound Traffic from Cloud Resources Only to a Specified Domain Name
- Using CFW to Defend Against Network Attacks
- Configuring a Protection Rule to Protect Traffic Between Two VPCs
- Configuring a Protection Rule to Protect SNAT Traffic
- Using CFW to Protect Enterprise Resources
- Using CFW to Protect EIPs Across Accounts
- Using CFW to Protect VPCs Across Accounts
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API Reference
- Before You Start
- API Overview
- API Calling
-
API
-
Firewall Management
- Creating a Firewall
- Obtaining the Status of a CFW Task
- Deleting a Firewall
- Querying the Firewall List
- Changing the East-West Firewall Protection Status
- Querying Firewall Details
- Obtaining East-West Firewall Information
- Creating an East-West Firewall
- Querying the Number of Protected VPCs
- Creating a Tag
- Deleting a Tag
- EIP Management
-
ACL Rule Management
- Creating an ACL Rule
- Deleting an ACL Rule
- Deleting ACL Rules in Batches
- Deleting the Number of Rule Hits
- Updating an ACL Rule
- Updating Rule Actions in Batches
- Setting the Priority of an ACL Protection Rule
- Querying a Protection Rule
- Querying Rule Tags
- Obtaining the Number of Rule Hits
- Viewing the Region List
- Checking the ACL Import Status
- Blacklist/Whitelist Management
- Address Group Management
- Service Group Management
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Domain Name Resolution and Domain Name Group Management
- Adding a Domain Name Group
- Deleting a Domain Name Group
- Updating a Domain Name Group
- Updating the DNS Server List
- Querying the Domain Name Group List
- Querying the DNS Server List
- Querying an IP Address for Domain Name Resolution
- Obtain the list of domain names in a domain name group
- Adding a Domain Name List
- Deleting a Domain Name List
- Viewing Domain Group Details
- Obtaining the DNS Resolution Result of a Domain Name
- Deleting Domain Groups in Batches
- IPS management
- Log Management
- Packet Capture Management
- Antivirus Management
- Alarm Configuration Management
- Tag Management
- IPS Management
-
Firewall Management
- Appendix
- SDK Reference
-
FAQs
-
About the Product
- Does CFW Support Off-Cloud Servers?
- What Are the QPS, New Connections, and Concurrent Connections Supported by CFW?
- Can CFW Be Shared Across Accounts?
- What Are the Differences Between CFW and WAF?
- What Are the Differences Between CFW, Security Groups, and Network ACLs?
- How Does CFW Control Access?
- What Are the Priorities of the Protection Settings in CFW?
- Can WAF, Advanced Anti-DDoS, and CFW Be Deployed Together?
- Can CFW Protect Resources Across Enterprise Projects?
- How Long Are CFW Logs Stored by Default?
- Regions and AZs
-
Troubleshooting
- What Do I Do If Service Traffic is Abnormal?
- Why Are Traffic and Attack Logs Incomplete?
- Why Does a Protection Rule Not Take Effect?
- What Do I Do If IPS Blocks Normal Services?
- Why Is No Data Displayed on the Access Control Logs Page?
- Why Is the IP Address Translated Using NAT64 Blocked?
- Why Some Permissions Become Invalid After a System Policy Is Granted to an Enterprise Project?
- What Do I Do If a Message Indicating Insufficient Permissions Is Displayed When I Configure LTS Logs?
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Network Traffic
- How Do I Calculate the Number of Protected VPCs and the Peak Protection Traffic at the VPC Border?
- How Does CFW Collect Traffic Statistics?
- What Is the Protection Bandwidth Provided by CFW?
- What Do I Do If My Service Traffic Exceeds the Protection Bandwidth?
- What Are the Differences Between the Data Displayed in Traffic Trend Module and the Traffic Analysis Page?
- How Do I Verify the Validity of an Outbound HTTP/HTTPS Domain Protection Rule?
- How Do I Obtain the Real IP Address of an Attacker?
- What Do I Do If a High Traffic Warning Is Received?
-
About the Product
- Videos
-
More Documents
-
User Guide (Ankara Region)
- Product Overview
- Checking the Dashboard
- Creating Cloud Firewall
- Enabling Internet Border Traffic Protection
- Enabling VPC Border Traffic Protection
-
Configuring Access Control Policies to Control Traffic
- Access Control Policy Overview
- Configuring Protection Rules to Block or Allow Traffic
- Adding Blacklist or Whitelist Items to Block or Allow Traffic
- Viewing Protection Information Using the Policy Assistant
- Managing Access Control Policies
- Managing IP Address Groups
- Domain Name Management
- Service Group Management
- Attack Defense
- Viewing Traffic Statistics
- Viewing CFW Protection Logs
- System Management
-
FAQs
-
About the Product
- Does CFW Support Off-Cloud Servers?
- What Are the QPS, New Connections, and Concurrent Connections Supported by CFW?
- Can CFW Be Shared Across Accounts?
- What Are the Differences Between CFW and WAF?
- What Are the Differences Between CFW, Security Groups, and Network ACLs?
- How Does CFW Control Access?
- What Are the Priorities of the Protection Settings in CFW?
- Can WAF and CFW Be Deployed Together?
- Troubleshooting
- Network Traffic
-
About the Product
- Change History
- API Reference (Ankara Region)
-
User Guide (Ankara Region)
- General Reference
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Using CFW to Defend Against Suspicious DNS Activities
You can use CFW to defend against suspicious DNS activities.
Application Scenarios
DNS is a basic and important part of most Internet requests. Once the DNS system is attacked, network services will be severely affected. Therefore, it is important to ensure DNS security. CFW provides intrusion prevention rules for detecting suspicious DNS activities. When CFW detects suspicious DNS activity intrusions, it can block intrusion activities and attack traffic in real time.
What Is a Suspicious DNS Activity?
A domain name system (DNS) is a query and conversion system used to convert domain names into IP addresses for computer connections. When a user enters the domain name of a website in the browser, the browser sends a domain name resolution request to the DNS server. The DNS server returns the IP address corresponding to the domain name. The user can obtain the corresponding website resource based on the IP address.
Suspicious DNS activities refer to abnormal DNS requests or responses over the network. Attackers exploit DNS defects or send excessive requests to attack DNS. As a result, the DNS sends abnormal requests or responses, causing domain name resolution errors, resolution timeout, or DNS breakdown. This affects user experience and may also bring serious consequences such as economic losses and even legal liabilities.
Common Suspicious DNS Activities and Their Harms
- DNS cache poisoning: An attacker exploits the vulnerabilities of a DNS server to take over the DNS server. By tampering with the cache of the DNS server, the attacker redirects user access to malicious websites and launches attacks such as phishing and malware download.
- DNS buffer overflow: An attacker exploits the vulnerabilities of the DNS server to send a large amount of malicious data to the cache of the server. As a result, the cache overflows and the malicious data overwrites the original valid data, causing attacks such as DNS response tampering, traffic redirection, and man-in-the-middle attacks.
How to Defend Against Suspicious DNS Activities
- Log in to the management console.
- Click
in the upper left corner of the management console and select a region or project.
- In the navigation pane on the left, click
and choose Security & Compliance > Cloud Firewall. The Dashboard page will be displayed.
- (Optional) Switch to another firewall instance: Select a firewall from the drop-down list in the upper left corner of the page.
- Click View Effective Rules under Basic Protection. The Basic Protection tab is displayed.
- Filter the rules for defending against suspicious DNS activities. In the filter above the list, select Suspicious-DNS-Activity from the Attack Types drop-down list.
- Enable protection in batches. Select multiple rules at a time and click Intercept.
NOTE:
Intercept: The firewall records the traffic that matches the current rule in attack event logs and blocks the traffic.
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