- What's New
- Function Overview
-
Service Overview
- What Is ELB?
- Product Advantages
- How ELB Works
- Application Scenarios
- Differences Between Dedicated and Shared Load Balancers
- Load Balancing on a Public or Private Network
- Network Traffic Paths
- Specifications of Dedicated Load Balancers
- Quotas and Constraints
- Billing (Dedicated Load Balancers)
- Permissions
- Product Concepts
- How ELB Works with Other Services
- Change History
- Getting Started
-
User Guide
-
Load Balancer
- Overview
- Preparations for Creating a Load Balancer
- Creating a Dedicated Load Balancer
- Creating a Shared Load Balancer
- Modifying the Bandwidth
- Changing the Specifications of a Dedicated Load Balancer
- Changing an IP Address
- Binding an IP Address to or Unbinding an IP Address from a Load Balancer
- Adding to or Removing from an IPv6 Shared Bandwidth
- Enabling or Disabling a Load Balancer
- Exporting the Load Balancer List
- Deleting a Load Balancer
- Listener
- Advanced Features of HTTP/HTTPS Listeners
- Backend Server Group
- Backend Server (Dedicated Load Balancers)
- Backend Server (Shared Load Balancers)
- Certificate
- Access Control
- TLS Security Policy
- Tag
- Access Logging
- Monitoring
- Auditing
- Permissions Management
- Quotas
- Appendix
- Change History
-
Load Balancer
- Best Practices
-
API Reference
- Before You Start
- API Overview
- Calling APIs
- APIs (V3)
- Examples
- Permissions and Supported Actions
- Appendix
- SDK Reference
-
FAQs
- Popular Questions
-
ELB Use
- Service Abnormality
-
ELB Functionality
- Can ELB Be Used Separately?
- Does ELB Support Persistent Connections?
- Does ELB Support FTP on Backend Servers?
- Can ELB Block DDoS Attacks and Secure Web Code?
- Is an EIP Assigned Exclusively to a Load Balancer?
- How Many Load Balancers and Listeners Can I Have?
- What Types of APIs Does ELB Provide? What Are Permissions of ELB?
- Can I Adjust the Number of Backend Servers When a Load Balancer is Running?
- Can Backend Servers Run Different OSs?
- Can I Configure Different Backend Ports for a Load Balancer?
- Are There Any Restrictions on the Frequency of Access from an IP Address?
- Can ELB Be Used Across Accounts or VPCs?
- Can Backend Servers Access the Ports of a Load Balancer?
- Can I Bind a Public IP Address Purchased from a Third-Party Cloud Provider to My Load Balancer?
- Can Both the Listener and Backend Server Group Use HTTPS?
- Can I Change the VPC and Subnet for My Load Balancer?
- Does ELB Support IPv6 Networks?
- Load Balancing Performance
-
Load Balancers
- What Is Quota?
- How Does ELB Distribute Traffic?
- How Can I Access a Load Balancer Across VPCs?
- How Can I Configure Load Balancing for Containerized Applications?
- Why Can't I Delete My Load Balancer?
- Do I Need to Configure Bandwidth for My Load Balancers?
- Can I Bind Multiple EIPs to a Load Balancer?
- Why Multiple IP Addresses Are Required When I Create or Enable a Load Balancer?
- Why Are Requests from the Same IP Address Routed to Different Backend Servers When the Load Balancing Algorithm Is Source IP Hash?
- Can Backend Servers Access the Internet Using the EIP of the Load Balancer?
- Will Traffic Routing Be Interrupted If the Load Balancing Algorithm Is Changed?
- What Is the Difference Between the Bandwidth Included in Each Specification of a Dedicated Load Balancer and the Bandwidth of an EIP?
- How Do I Combine ELB and WAF?
-
Listeners
- What Are the Relationships Between Load Balancing Algorithms and Sticky Session Types?
- Can I Bind Multiple Certificates to a Listener?
- Do HTTP and HTTP Listeners Support the X-Forwarded-Host Header?
- Will ELB Stop Distributing Traffic Immediately After a Listener Is Deleted?
- Does ELB Have Restrictions on the File Upload Speed and Size?
- Can Multiple Load Balancers Route Requests to One Backend Server?
- How Is WebSocket Used?
- What Are the Three Timeouts of a Listener and What Are the Default Durations?
- Why Can't I Select the Target Backend Server Group When Adding or Modifying a Listener?
- Why Cannot I Add a Listener to a Dedicated Load Balancer?
-
Backend Servers
- Why Is the Interval at Which Backend Servers Receive Health Check Packets Different from What I Have Configured?
- Can Backend Servers Access the Internet After They Are Associated with a Load Balancer?
- Can ELB Distribute Traffic Across Servers That Are Not Provided by Huawei Cloud?
- Can ELB Route Traffic Across Regions?
- Does Each Backend Server Need an EIP to Receive Requests from a Public Network Load Balancer?
- How Do I Check the Network Conditions of a Backend Server?
- How Can I Check the Network Configuration of a Backend Server?
- How Do I Check the Status of a Backend Server?
- How Long Is the Timeout Duration of Connections Between a Load Balancer and Backend Servers?
- When Is a Backend Server Considered Healthy?
- How Do I Check Whether a Backend Server Can Be Accessed Through an EIP?
- Why Is the Number of Active Connections Monitored by Cloud Eye Different from the Number of Connections Established with the Backend Servers?
- Why Can I Access Backend Servers After a Whitelist Is Configured?
- When Will Modified Weights Take Effect?
- How Much Time Is Required for a Load Balancer to Disconnect from Backend Servers After The Servers Are Removed?
- Why Must the Subnet Where the Load Balancer Resides Have at Least 16 Available IP Addresses for Enabling IP as a Backend?
-
Health Checks
- How Do I Troubleshoot an Unhealthy Backend Server?
- Why Is the Interval at Which Backend Servers Receive Health Check Packets Different from the Configured Interval?
- How Does ELB Perform UDP Health Checks? What Are the Precautions for UDP Health Checks?
- Why Does ELB Frequently Send Requests to Backend Servers During Health Checks?
- When Does a Health Check Start?
- Do Maximum Retries Include Health Checks That Consider Backend Servers Unhealthy?
- What Do I Do If a Lot of Access Logs Are Generated During Health Checks?
- What Status Codes Will Be Returned If Backend Servers Are Identified as Healthy?
- Obtaining Source IP Addresses
-
HTTP/HTTPS Listeners
- Which Protocol Should I Select for the Backend Server Group When Adding an HTTPS Listener?
- Why Is There a Security Warning After a Certificate Is Configured?
- Why Is a Forwarding Policy in the Faulty State?
- Why Can't I Add a Forwarding Policy to a Listener?
- Why Cannot I Select an Existing Backend Server Group When Adding a Forwarding Policy?
- Sticky Sessions
- Certificates
- Monitoring
- Billing
- Videos
Show all
Access Control
Access control allows you to add a whitelist or blacklist to specify IP addresses that are allowed or denied to access a listener. A whitelist allows specified IP addresses to access the listener, while a blacklist denies access from specified IP addresses.
- Adding the whitelist or blacklist may cause risks.
- Once the whitelist is set, only the IP addresses specified in the whitelist can access the listener.
- Once the blacklist is set, the IP addresses specified in the blacklist cannot access the listener.
- Whitelists and blacklists do not conflict with inbound security group rules. Whitelists define the IP addresses that are allowed to access the listeners, while blacklists specify IP addresses that are denied to access the listeners. Inbound security group rules control access to backend servers by specifying the protocol, ports, and IP addresses.
- Access control does not restrict the ping command. You can still ping backend servers from the restricted IP addresses.
- Access control policies only take effect for new connections, but not for connections that have been established. If a whitelist is configured for a listener but IP addresses that are not in the whitelist can access the backend server associated with the listener, one possible reason is that a persistent connection is established between the client and the backend server. To deny IP addresses that are not in the whitelist from accessing the listener, the persistent connection between the client and the backend server needs to be disconnected.
Configuring Access Control
- Log in to the management console.
- In the upper left corner of the page, click
and select the desired region and project.
- Hover on
in the upper left corner to display Service List and choose Network > Elastic Load Balance.
- Locate the load balancer and click its name.
- You can configure access control for a listener in either of the following ways:
- On the Listeners page, locate the listener and click Configure in the Access Control column.
- Click the name of the target listener. On the Summary page, click Configure on the right of Access Control.
- In the displayed Configure Access Control dialog box, configure parameters as shown in Table 1.
Table 1 Parameter description Parameter
Description
Example Value
Access Control
Specifies how access to the listener is controlled. Three options are available:
- All IP addresses: All IP addresses can access the listener.
- Whitelist: Only IP addresses in the IP address group can access the listener.
- Blacklist: IP addresses in the IP address group are not allowed to access the listener.
Blacklist
IP Address Group
Specifies the IP address group associated with a whitelist or blacklist. If there is no IP address group, create one first. For more information, see IP Address Group Overview.
ipGroup-b2
Access Control
If you have set Access Control to Whitelist or Blacklist, you can enable or disable access control.
- Only after you enable access control, the whitelist or blacklist takes effect.
- If you disable access control, the whitelist or blacklist does not take effect.
N/A
- Click OK.
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.