Introduction to the Routing Table
Glossary
Default Routing Table: The routing table which the system creates for VPC by default when creating VPC. The newly established subnet will be bound to the default routing table. The default routing table cannot be deleted or edited, and all the rules in the default routing table are system routes.
Custom Routing Table: The routing table created by users on their own. Custom routing rules can be added. Users can create, delete, and edit custom routing tables. Please note that system routes in the custom routing table are only visible and cannot be edited.
System Route: The route rule added to the routing table by the system by default. System routes are only visible.
Custom Route: Routing rules defined by users. Routing rules include the destination address, next-hop type, and next-hop. Custom routes can be added, edited, and deleted. The routing table takes effect at the subnet granularity. Each subnet must be bound to and can only be bound to one routing table, and one routing table can be bound to multiple subnets.
Route Rule Type
Routing table rule’s next hop type enumeration is as follows:
| Next Hop Type | Next Hop | Explanation |
|---|---|---|
| LOCAL | LOCAL | System Route. Every network segment in each VPC will add a LOCAL route, indicating that by default it can circulate within the VPC. |
| VPC Interconnection | vnet id | System Route, added by system by default after VPC is linked. |
| Internet Gateway | Internet Gateway | System Route, a designated exit to the public networks. If the cloud resources are bound with EIP, the default exit is EIP; otherwise if the subnet is bound with NAT gateway, the default exit is NAT gateway. |
| Public Services | Public Services | System Route, pointing to public services provided by DezaiCloud, such as DNS, YUM sources, as well as proxy addresses of ULB, and health check addresses, etc. |
| CUSTOM | CUSTOM | System route, SPECIAL service within DezaiCloud, such as UAEK and other business purposes |
| IPSecVPN | vpngw id | Custom Route, the routes added to the VPC pointing to IPSec VPN gateway after using the IPSec VPN product. The system currently adds it automatically and does not allow customers to add it temporarily. |
| Internal VIP | vip id | Custom Route. The next hop is VIP. |
| Instance | uhost id (phost id) | Custom Route. The next hop is a cloud host or a physical cloud host. |
Usage Restrictions:
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The destination address segment in the route rules can overlap but cannot be completely identical. If it matches the destination address of multiple route rules at the same time, the priority is determined by the longest prefix matching algorithm.
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The types of next hop supported by custom route rules are intranet VIP and instance (cloud host, physical cloud host).
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Custom route rules cannot be added to the default routing table. If custom rules are needed, you can create a custom routing table and add custom route rules.
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Each routing table supports up to 50 custom route rules.