Chapter 8
| General Security Measures
DHCP Snooping
– 247 –
will be performed on any untrusted ports within the VLAN as specified by the
ip
dhcp snooping trust
command.
◆
When the DHCP snooping is globally disabled, DHCP snooping can still be
configured for specific VLANs, but the changes will not take effect until DHCP
snooping is globally re-enabled.
◆
When DHCP snooping is globally enabled, and DHCP snooping is then disabled
on a specific VLAN, all dynamic bindings learned for this VLAN are removed
from the binding table.
Example
This example enables DHCP snooping for VLAN 1.
Console(config)#ip dhcp snooping vlan 1
Console(config)#
Related Commands
ip dhcp snooping (242)
ip dhcp snooping trust (247)
ip dhcp snooping trust
This command configures the specified interface as trusted. Use the
no
form to
restore the default setting.
Syntax
[
no
]
ip dhcp snooping trust
Default Setting
All interfaces are untrusted
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
◆
A trusted interface is an interface that is configured to receive only messages
from within the network. An untrusted interface is an interface that is
configured to receive messages from outside the network or fire wall.
◆
Set all ports connected to DHCP servers within the local network or fire wall to
trusted, and all other ports outside the local network or fire wall to untrusted.
◆
When DHCP snooping is enabled globally using the
ip dhcp snooping
command, and enabled on a VLAN with
ip dhcp snooping vlan
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.
Содержание EX-3524
Страница 2: ......
Страница 28: ...Figures 28 ...
Страница 34: ...Section I Getting Started 34 ...
Страница 58: ...Chapter 1 Initial Switch Configuration Setting the System Clock 58 ...
Страница 72: ...Chapter 2 Using the Command Line Interface CLI Command Groups 72 ...
Страница 156: ...Chapter 5 SNMP Commands Notification Log Commands 156 ...
Страница 164: ...Chapter 6 Remote Monitoring Commands 164 ...
Страница 218: ...Chapter 7 Authentication Commands Management IP Filter 218 ...
Страница 268: ...Chapter 8 General Security Measures Port based Traffic Segmentation 268 ...
Страница 292: ...Chapter 9 Access Control Lists ACL Information 292 ...
Страница 312: ...Chapter 10 Interface Commands Power Savings 312 ...
Страница 324: ...Chapter 11 Link Aggregation Commands Trunk Status Display Commands 324 ...
Страница 366: ...Chapter 15 Address Table Commands 366 ...
Страница 428: ...Chapter 17 VLAN Commands Configuring Voice VLANs 428 ...
Страница 572: ...Chapter 25 IP Interface Commands IPv6 Interface 572 ...
Страница 578: ...Section I Appendices 578 ...
Страница 594: ...Appendix C Customer Support Manuals 594 ...