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Chapter 12
| Security Measures
DHCP Snooping
–
316
–
Configuring Ports
for DHCP Snooping
Use the Security > DHCP Snooping (Configure Interface) page to configure switch
ports as trusted or untrusted.
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.
◆
When DHCP snooping is enabled both globally and on a VLAN, DHCP packet
filtering will be performed on any untrusted ports within the VLAN.
◆
When an untrusted port is changed to a trusted port, all the dynamic DHCP
snooping bindings associated with this port are removed.
◆
Set all ports connected to DHCP servers within the local network or fire wall to
trusted state. Set all other ports outside the local network or fire wall to
untrusted state.
◆
The format for TR101 option 82 is: “<IP> eth <SID>/<PORT>[:<VLAN>]”. Note
that the SID (Switch ID) is always 0. By default the PVID is added to the end of
the TR101 field for untagged packets. For tagged packets, the VLAN ID is always
added.
Parameters
These parameters are displayed:
◆
Trust Status
–
Enables or disables a port as trusted. (Default: Disabled)
◆
Max Number
–
The maximum number of DHCP clients which can be
supported per interface. (Range: 1-32; Default: 16)
◆
Circuit ID
–
Specifies DHCP Option 82 circuit ID suboption information.
■
Mode
–
Specifies the default string “VLAN
-Unit-
Port” or an arbitrary string.
(Default: VLAN-Unit-Port)
■
Value
–
An arbitrary string inserted into the circuit identifier field.
(Range: 1-32 characters)
■
TR101 VLAN Field
–
Adds
“:VLAN”
in TR101 field for untagged packets.
Web Interface
To configure global settings for DHCP Snooping:
1.
Click IP Service, DHCP, Snooping.
2.
Select Configure Interface from the Step list.
3.
Set any ports within the local network or firewall to trusted.
Содержание GEL-5261
Страница 14: ...14 Contents Glossary 551 Index 559...
Страница 26: ...26 Figures...
Страница 30: ...30 Section I Getting Started...
Страница 42: ...42 Section II Web Configuration IP Services on page 527...
Страница 45: ...Chapter 2 Using the Web Interface NavigatingtheWebBrowserInterface 45 Figure 1 Dashboard...
Страница 62: ...62 Chapter 2 Using the Web Interface NavigatingtheWebBrowserInterface...
Страница 180: ...Chapter 6 Address Table Settings Issuing MAC Address Traps 180...
Страница 208: ...Chapter 8 Congestion Control Storm Control 208 Figure 121 Configuring Storm Control...
Страница 218: ...218 Chapter 9 Class of Service Layer 3 4 Priority Settings Figure 128 Configuring DSCP to Queue Mapping...
Страница 228: ...228 Chapter 10 Quality of Service Attaching a Policy Map to a Port...
Страница 332: ...Chapter 12 Security Measures ARP Inspection 332 Figure 207 Displaying the ARP Inspection Log...
Страница 436: ...Chapter 13 Basic Administration Protocols LBD Configuration 436...
Страница 488: ...488 Chapter 14 Multicast Filtering Filtering MLD Query Packets on an Interface...
Страница 498: ...Chapter 15 IP Tools Address Resolution Protocol 498...
Страница 517: ...517 Chapter 16 IP Configuration Setting the Switch s IP Address IP Version 6 interface...
Страница 542: ...540 Section III Appendices...
Страница 560: ...Glossary 558...
Страница 569: ...567 Index web interface access requirements 43 configuration buttons 46 menu list 47 panel display 46...
Страница 570: ...568 Index E062017 ST R01...