SMC Networks SMC8150L2 manual Dhcp Snooping Commands, Ip dhcp snooping

DHCP Snooping Commands 4

Example

Console#show ip source-guard binding			VLAN Interface
MacAddress	IpAddress	Lease(sec) Type

----------------- --------------- ---------- -------------------- ---- ----

11-22-33-44-55-66 192.168.0.99	0 Static	1 Eth 1/5
Console#

DHCP Snooping Commands

DHCP snooping allows a switch to protect a network from rogue DHCP servers or other devices which send port-related information to a DHCP server. This information can be useful in tracking an IP address back to a physical port. This section describes commands used to configure DHCP snooping.

Table 4-78 DHCP Snooping Commands

Command	Function	Mode	Page
ip dhcp snooping	Enables DHCP snooping globally	GC	4-231
ip dhcp snooping vlan	Enables DHCP snooping on the specified VLAN	GC	4-233
ip dhcp snooping trust	Configures the specified interface as trusted	IC	4-234
ip dhcp snooping verify	Verifies the client’s hardware address stored in the DHCP	GC	4-235
mac-address	packet against the source MAC address in the Ethernet header
ip dhcp snooping	Enables or disables DHCP Option 82 information relay	GC	4-235
information option
ip dhcp snooping	Sets the information option policy for DHCP client packets that	GC	4-236
information policy	include Option 82 information
show ip dhcp snooping	Shows the DHCP snooping configuration settings	PE	4-237
show ip dhcp snooping	Shows the DHCP snooping binding table entries	PE	4-237
binding

ip dhcp snooping

This command enables DHCP snooping globally. Use the no form to restore the default setting.

Syntax

[no] ip dhcp snooping

Default Setting

Disabled

Command Mode

Global Configuration

Command Usage

•Network traffic may be disrupted when malicious DHCP messages are received from an outside source. DHCP snooping is used to filter DHCP messages received on an unsecure interface from outside the network or

4-231