Cisco IE-3000-8TC Command Reference

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Cisco IE 3000 Switch Command Reference
OL-13019-01
Chapter 2 IE 3000 Switch Cisco IOS Commands
ip dhcp snooping database
Usage Guidelines The DHCP snooping binding database can have up to 8192 bindings.
To ensure that the lease time in the database is accurate, we recommend that Network Time Protocol
(NTP) is enabled and configured for these features:
• NTP authentication
• NTP peer and server associations
• NTP broadcast service
• NTP access restrictions
• NTP packet source IP address
If NTP is configured, the switch writes binding changes to the binding file only when the switch system
clock is synchronized with NTP.
Because both NVRAM and the flash memory have limited storage capacities, we recommend that you
store a binding file on a TFTP server. You must create an empty file at the configured URL on
network-based URLs (such as TFTP and FTP) before the switch can first write bindings to the binding
file at that URL.
Use the ip dhcp snooping database flash:/filename command to save the DHCP snooping binding
database in the NVRAM. If you set the ip dhcp snooping database timeout command to 0 seconds and
the database is being written to a TFTP file, if the TFTP server goes down, the database agent continues
to try the transfer indefinitely. No other transfer can be initiated while this one is in progress. This might
be inconsequential because if the server is down, no file can be written to it.
Use the no ip dhcp snooping database command to disable the agent.
Use the no ip dhcp snooping database timeout command to reset the timeout value.
Use the no ip dhcp snooping database write-delay command to reset the write-delay value.
Examples This example shows how to store a binding file at an IP address of 10.1.1.1 that is in a directory called
directory. A file named file must be present on the TFTP server.
Switch(config)# ip dhcp snooping database tftp://10.1.1.1/directory/file
This example shows how to store a binding file called file01.txt in the NVRAM:
Switch(config)# ip dhcp snooping database flash:file01.txt
You can verify your settings by entering the show ip dhcp snooping database privileged EXEC
command.
Related Commands Command Description
ip dhcp snooping Enables DHCP snooping on a VLAN.
ip dhcp snooping binding Configures the DHCP snooping binding database.
show ip dhcp snooping database Displays the status of DHCP snooping database agent.

Cisco IE-3000-8TC Specifications

General

Switching Capacity	16 Gbps
MAC Address Table Size	8000
Uplink Ports	2 x 10/100/1000Base-T or SFP (Small Form-Factor Pluggable)
Operating Temperature	-40°C to 70°C
Mounting	DIN rail
Ports	8 x Ethernet 10/100Base-TX ports
Jumbo Frame Support	Yes