CLI Reference Guide-R04

Chapter 9 | General Security Measures
DHCPv4 Snooping
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show web-auth
summary
This command displays a summary of web authentication port parameters and
statistics.
Command Mode
Privileged Exec
Example
Console#show web-auth summary
Global Web-Auth Parameters
System Auth Control : Enabled
Port Status Authenticated Host Count
---- ------ ------------------------
1/ 1 Disabled 0
1/ 2 Enabled 8
1/ 3 Disabled 0
1/ 4 Disabled 0
1/ 5 Disabled 0
.
.
.
DHCPv4 Snooping
DHCPv4 snooping allows a switch to protect a network from rogue DHCPv4 servers
or other devices which send port-related information to a DHCPv4 server. This
information can be useful in tracking an IP address back to a physical port. This
section describes commands used to configure DHCPv4 snooping.
Table 58: DHCP Snooping Commands
Command Function Mode
ip dhcp snooping Enables DHCP snooping globally GC
ip dhcp snooping information
option
Enables or disables the use of DHCP Option 82
information, and specifies frame format for the remote-id
GC
ip dhcp snooping information
option encode no-subtype
Disables use of sub-type and sub-length for the
CID/RID in Option 82 information
GC
ip dhcp snooping information
option remote-id
Sets the remote ID to the switch’s IP address, MAC
address, or arbitrary string, TR-101 compliant node
identifier, or removes VLAN ID from the end of the TR101
field
GC
ip dhcp snooping information
option tr101 board-id
Sets the board identifier used in Option 82 information
based on TR-101 syntax
GC
ip dhcp snooping limit rate Sets the maximum number of DHCP packets that can be
trapped for DHCP snooping
GC
ip dhcp snooping verify
mac address
Verifies the client’s hardware address stored in the DHCP
packet against the source MAC address in the Ethernet
header
GC
ip dhcp snooping vlan Enables DHCP snooping on the specified VLAN GC
ip dhcp snooping information
option circuit-id
Enables or disables the use of DHCP Option 82
information circuit-id suboption
IC