User's Manual

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there is no binding relationship on this interface. After source IPaddress monitoring is enabled, the switch
rejected forwarding all IP packets. After the TFTP server is configured for interface binding backup, the binding
relationship will be backed up to the server through the TFTP protocol. After the switch is restarted, the switch
automatically downloads the binding list from the TFTP server, securing the normal running of the network.
Run the following commands in global configuration mode.
Command Operation
ip dhcp-relay snooping database-agent ip-
address
Configures the IP address of the TFTP
server which is to back up interface
binding.
no ip dhcp-relay snooping database-agent ip-
address
Cancels the TFTP Server for backing up
interface binding.
44.1.13 Setting a File Name for Interface Binding Backup
When backing up the interface binding relationship, the corresponding file name will be saved on the TFTP
server. In this way, different switches can back up their own interface binding relationships to the same TFTP
server.
Run the following commands in global configuration mode.
Command Operation
ip dhcp-relay snooping db-file
name [timestamp]
Configures a file name for interface binding backup.
no ip dhcp-relay snooping db-
file
Cancels a file name for interface binding backup.
44.1.14 Setting the Interval for Checking Interface Binding Backup
The MAC-to-IP binding relationship on an interface changes dynamically. Hence, you need check whether the
binding relationship updates after a certain interval. If the binding relationship updates, it need be backed up
again. The default time interval is 30mins.
Run the following commands in global configuration mode.
Command Operation
ip dhcp-relay snooping write-
immediately
Configures DHCP Snooping immediate backup when the
binding information changes.
no ip dhcp-relay snooping {write-time | write-immediately}
Resumes the interval of checking interface binding
backup to the default settings.
ip dhcp-relay snooping write-
time num
Configures the interval for checking interface binding
backup. The unit is min.