Release R.11.12 Enhancements
Leased IP address
The switch can be configured to store the bindings at a specific URL so they will not be lost if the
switch is rebooted. If the switch is rebooted, it will read its binding database from the specified
location. To configure this location use this command.
Syntax: [no] dhcp-snooping database [file<tftp://<ip-address>/<ascii-string>>]
A message is logged in the system event log if the DHCP binding database fails to update.
To display the contents of the DHCP snooping binding database, enter this command.
show dhcp-snooping binding
N o t e
If a lease database is configured, the switch drops all DHCP packets until the lease database is read.
This only occurs when the switch reboots and is completed quickly. If the switch is unable to read
the lease database from the tftp server, it waits until that operation times out and then begins
forwarding DHCP packets.
Enabling Debug Logging
To enable debug logging for DHCP snooping, use this command.
Syntax: [no] debug dhcp-snooping [agent | event | packet]
Must be in Uniform Resource Locator (URL)
format — "tftp://ip-address/ascii-string". The
maximum filename length is 63 characters.
Number of seconds to wait before writing to the
database. Default = 300 seconds.
Number of seconds to wait for the database file
transfer to finish before returning an error. A
value of zero (0) means retry indefinitely.
Default = 300 seconds.
Displays DHCP snooping agent messages.
Displays DHCP snooping event messages.
Displays DHCP snooping packet messages.