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Load Balancer

Configuring a forwarding rule

Forwarding rule description

Introduction

Forwarding rules are used to direct requests for specified domain names and URLs to designated backend server groups.

You can configure multiple forwarding rules for one Layer 7 listener.

Classification

Category	Explanation
Default forwarding rule	After successfully creating the Layer 7 listener, the system automatically creates forwarding rules. The default forwarding rule has an empty domain name and a URL of /, indicating that requests from any domain name and URL can be forwarded to the specified backend server group.
Custom forwarding rules	Custom forwarding rule: Forwarding rule added manually for Layer 7 listeners according to business needs. Custom forwarding rules can forward or redirect access requests matching domains and URLs.

After August 30, 2021:

Newly created listeners must have a default forwarding rule to forward requests that do not match any rule.

Existing listeners: Please refer to Creating a listener to configure the default Server Group for a Layer 7 listener. Otherwise, you will not be able to modify other attributes of the listener, and you will not be able to create forwarding rules with an empty domain name.

Domain name and URL

Domain name

Domain name supports two configuration modes: precise domain name and wildcard domain name.

Exact domain name: An exact domain name that complies with domain name specifications. For example www.test.com

Wildcard domain: Use wildcard * to replace one or more characters, * is only supported at the beginning or end of a domain name, it can only appear once per domain name, and can only be placed around . Allowed placement before or after the <a i=3>.</a>

Allowed formats: *.test.com, www.test.*

Disallowed formats: www.*.com, *.test.*, *.*.com, *aaa.com

URL paths start with /, e.g., /, /abc/read. If not configured, the default is /.

You can configure the domain name only, URL only, or both domain name and URL according to your business needs.

If only the domain name is configured, the URL defaults to /, meaning it forwards requests matching any URL under that domain name. For example, if the domain name is configured as www.test.com, requests to www.test.com/lb/ or www.test.com/lb/create will both match this forwarding rule.

If only the URL is configured, the domain name defaults to empty, meaning it forwards requests matching that URL on any domain. For example, if the URL is set to /lb, requests to www.test.com/lb or www.test.cn/lb will both match this forwarding rule.

If both the domain name and URL are configured, it forwards requests that match both the specified domain name and URL.

Matching description

Matching process

When the Layer 7 listener receives a request, it forwards the request to the corresponding backend server group by matching the domain name and URL based on the forwarding rule configuration. The matching process is as follows:

If the received request contains a domain name, domain matching is performed in the priority order of exact domain name > wildcard domain starting with * > wildcard domain ending with *

If a matching domain name exists, continue matching the URL according to the longest match principle.

If a matching URL exists, forward the request to the backend server group of the corresponding rule.

If there is no matching URL, forward the request to the backend server group of the default forwarding rule.

If no matching domain name exists, continue matching forwarding rules with "no domain name, URL path only" based on the longest match principle.

If a matching URL exists, forward the request to the backend server group of the corresponding rule.

If there is no matching URL or no forwarding rule with "no domain name, URL path only," forward the request to the backend server group of the default forwarding rule.

tip

Domain matching for forwarding rules is case-insensitive, while URL matching is case-sensitive. When configuring forwarding rules for a Layer 7 listener, configure the URLs with the correct case according to the actual URLs.

Matching examples

For example, a Layer 7 listener has the following forwarding rules configured in sequence:

Domain name	URL	Forwarding action
-	/	Forward to default backend server group RS0
-	/lb	Forward to RS1
-	/abc/create	Forward to RS2
www.test.com	/	Forward to RS3
*.test.com	/lb/create	Forward to RS4
example.test.*	/lb/create	Forward to RS5

The matching rules for the following requests are as follows:

Request	Match backend server group	Explanation
www.test.com/	RS3	Exact domain name and URL match, forward to RS3.
www.test.com/lb	RS3	Exact domain match. URL matches based on the longest match rule and forwards to RS3.
example.test.com/lb/create	RS4	Wildcard domain match *.test.com, exact URL match, forward to RS4.
example.test.com/lb/create/abc	RS4	Wildcard domain matching *.test.com, URL matched by longest match principle, forwarding to RS4.
clb.test.com/abc	-	Wildcard domain match *.test.com, URL not matched, return 404 error (because requested URL is not the root directory).
clb.test.com/	-	wildcard domain matching *.test.com returns error 403 if the URL is not matched (because the request URL is the root directory).
www.test.cn/lb	RS1	No domain matched. Fully matched URL with no domain forwarding rule, forward to RS1.
test.com/abc/create/lb	RS2	No domain name matched. According to the longest match principle, match the URL of the no domain forwarding rule and forward it to RS2.
www.b.com/ab	RS0	No matching domain or URL found, forwarding to the default backend server group RS0.

Last updated: 2026.08.06 14:31:17