Configuring DHCP snooping entries backup
DHCP snooping entries cannot survive a reboot. If the DHCP snooping device is rebooted, security modules (such as IP source guard) that use DHCP snooping entries to authenticate users will reject requests from clients until new entries are learned.
The DHCP snooping entries backup feature enables you to store DHCP snooping entries in a file. When the DHCP snooping device reboots, it reads DHCP snooping entries from this file.
After DHCP snooping is disabled with the undo dhcp-snooping command, the device will delete all DHCP snooping entries, including those stored in the file.
To configure DHCP snooping entries backup:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Specify the name of the file for storing DHCP snooping entries. | dhcp-snooping binding database filename filename | Not specified by default. DHCP snooping entries are stored immediately after this command is used and then updated at the interval set by the dhcp-snooping binding database update interval command. |
3. Back up DHCP snooping entries to the file. | dhcp-snooping binding database update now | Optional. DHCP snooping entries will be stored to the file each time this command is used. |
4. Set the interval at which the DHCP snooping entry file is refreshed. | dhcp-snooping binding database update interval minutes | Optional. By default, the file is not refreshed periodically. |