C
LIENT
S
ECURITY
C
OMMANDS
22-18
Command Usage
• An untrusted interface is an interface that is configured to receive
messages from outside the network or firewall. A trusted interface is
an interface that is configured to receive only messages from within
the network.
• When DHCP snooping enabled globally using the
ip dhcp snooping
command (page 22-11), and enabled on a VLAN with this command,
DHCP packet filtering will be performed on any untrusted ports
within the VLAN according to the default status, or as specifically
configured for an interface with the
no ip dhcp snooping trust
command.
• When an untrusted port is changed to a trusted port, all the dynamic
DHCP snooping bindings associated with this port are removed. All
static bindings are retained, but will have no effect unless the port is
changed back to the untrusted state.
•
Additional considerations when the switch itself is a DHCP client
– The port(s)
through which it submits a client request to the DHCP server must be
configured as trusted.
Example
This example sets port 5 to untrusted.
Related Commands
ip dhcp snooping (22-11)
ip dhcp snooping vlan (22-13)
ip dhcp snooping binding (22-14)
show ip dhcp snooping
This command shows the DHCP snooping configuration settings.
Command Mode
Privileged Exec
Console(config)#interface ethernet 1/5
Console(config-if)#no ip dhcp snooping trust
Console(config-if)#
Summary of Contents for 7824M/FSW - annexe 1
Page 2: ......
Page 24: ...TABLE OF CONTENTS xxiv ...
Page 28: ...TABLES xxviii ...
Page 32: ...FIGURES xxxii Figure 16 3 DNS Cache 16 7 ...
Page 34: ...GETTING STARTED ...
Page 46: ...SYSTEM DEFAULTS 1 12 ...
Page 62: ...SWITCH MANAGEMENT ...
Page 74: ...CONFIGURING THE SWITCH 3 12 ...
Page 112: ...BASIC MANAGEMENT TASKS 4 38 ...
Page 168: ...USER AUTHENTICATION 6 30 ...
Page 223: ...SHOWING PORT STATISTICS 9 33 Figure 9 12 Port Statistics ...
Page 230: ...ADDRESS TABLE SETTINGS 10 6 ...
Page 304: ...CLASS OF SERVICE 13 16 ...
Page 316: ...QUALITY OF SERVICE 14 12 ...
Page 338: ...MULTICAST FILTERING 15 22 ...
Page 346: ...DOMAIN NAME SERVICE 16 8 ...
Page 348: ...COMMAND LINE INTERFACE IP Interface Commands 35 1 ...
Page 362: ...OVERVIEW OF COMMAND LINE INTERFACE 17 14 ...
Page 494: ...USER AUTHENTICATION COMMANDS 21 48 ...
Page 514: ...CLIENT SECURITY COMMANDS 22 20 ...
Page 540: ...ACCESS CONTROL LIST COMMANDS 23 26 ...
Page 558: ...INTERFACE COMMANDS 24 18 ...
Page 576: ...MIRROR PORT COMMANDS 26 4 ...
Page 582: ...RATE LIMIT COMMANDS 27 6 ...
Page 616: ...SPANNING TREE COMMANDS 29 28 ...
Page 644: ...VLAN COMMANDS 30 28 ...
Page 664: ...CLASS OF SERVICE COMMANDS 31 20 ...
Page 678: ...QUALITY OF SERVICE COMMANDS 32 14 ...
Page 720: ...APPENDICES ...
Page 726: ...SOFTWARE SPECIFICATIONS A 6 ...
Page 730: ...TROUBLESHOOTING B 4 ...
Page 746: ...INDEX Index 6 ...
Page 747: ......