The ip prefix-limit command configures a limit on the number of IPv4 public route prefixes.
The undo ip prefix-limit command restores the default configuration.
By default, the maximum number of IPv4 public route prefixes is not limited.
ip prefix-limit number { alert-percent [ route-unchanged ] | simply-alert }
undo ip prefix-limit
| Parameter | Description | Value |
|---|---|---|
| number | Specifies the maximum number of IPv4 public route prefixes. |
The value is an integer, and the minimum value is 1. The maximum number is determined by the license file. |
| alert-percent | Specifies the percentage of the maximum number of IPv4 public route prefixes. If you specify alert-percent in the command, when the number of IPv4 public route prefixes exceeds the value calculated by (number x alert-percent) /100, an alarm is generated. Additional IPv4 public route prefixes can still be added to the routing table until the number of IPv4 public route prefixes reaches number. Subsequent route prefixes are discarded. |
The value is an integer ranging from 1 to 100. |
| route-unchanged | Indicates that the routing table remains unchanged.
If you decrease alert-percent after the number
of IPv4 public route prefixes exceeds number, whether
the routing table remains unchanged is determined by route-unchanged.
By default, the system deletes the routes from the routing table and re-adds routes. |
- |
| simply-alert | Indicates the following function: If you specify simply-alert in the command, new IPv4 public route prefixes can still be added to the routing table and only an alarm is generated after the number of IPv4 public route prefixes exceeds number. However, when the total number of private and public route prefixes reaches the limit on the number of unicast route prefixes specified in the PAF file, subsequent IPv4 public route prefixes are discarded. |
- |
Usage Scenario
If the switch imports a large number of routes, system performance may be affected when processing services because the routes consume a lot of system resources. To improve system security and reliability, you can run the ip prefix-limit command to configure a limit on the number of IPv4 public route prefixes. When the number of IPv4 public route prefixes exceeds the limit, an alarm is generated, prompting you to check whether unneeded IPv4 public route prefixes exist.
Configuration Impact
After the ip prefix-limit command is run, the switch may discard unneeded IPv4 public route prefixes.
Precautions
If you run the ip prefix-limit command for several times, the last configuration overrides previous configurations.