C
HAPTER
4
| Configuring the Switch
Configuring DHCP Relay and Option 82 Information
– 142 –
C
ONFIGURING
DHCP R
ELAY
AND
O
PTION
82 I
NFORMATION
The switch supports DHCP relay service for attached host devices. If a
subnet does not include a DHCP server, you can relay DHCP client requests
to a DHCP server on another subnet.
When DHCP relay is enabled and the switch sees a DHCP request
broadcast, it inserts its own IP address into the request (so that the DHCP
server knows the subnet of the client), then forwards the packet to the
DHCP server. When the server receives the DHCP request, it allocates a
free IP address for the DHCP client from its defined scope for the DHCP
client's subnet, and sends a DHCP response back to the switch. The switch
then broadcasts the DHCP response to the client.
DHCP also provides a mechanism for sending information about the switch
and its DHCP clients to the DHCP server. Known as DHCP Option 82, it
allows compatible DHCP servers to use the information when assigning IP
addresses, or to set other services or policies for clients.
Using DHCP Relay Option 82, clients can be identified by the VLAN and
switch port to which they are connected rather than just their MAC
address. DHCP client-server exchange messages are then forwarded
directly between the server and client without having to flood them to the
entire VLAN.
In some cases, the switch may receive DHCP packets from a client that
already includes DHCP Option 82 information. The switch can be configured
to set the action policy for these packets. Either the switch can drop
packets that already contain Option 82 information, keep the existing
information, or replace it with the switch's relay information.
P
ARAMETERS
The following parameters are displayed on the DHCP Relay Configuration
page:
◆
Relay Mode
- Enables or disables the DHCP relay function.
(Default: Disabled)
◆
Relay Server
- IP address of DHCP server to be used by the switch's
DHCP relay agent.
◆
Relay Information Mode
- Enables or disables the DHCP Relay Option
82 support. Note that Relay Mode must also be enabled for Relay
Information Mode to take effect. (Default: Disabled)
◆
Relay Information Policy
- Sets the DHCP relay policy for DHCP
client packets that include Option 82 information.
■
Replace
- Overwrites the DHCP client packet information with the
switch's relay information. (This is the default.)
■
Keep
- Retains the client's DHCP information.
Содержание 8028L2
Страница 1: ...MANAGEMENT GUIDE TigerSwitchTM 10 100 1000 28 Port Gigabit Ethernet Switch SMC8028L2 ...
Страница 6: ...ABOUT THIS GUIDE 6 ...
Страница 22: ...FIGURES 22 ...
Страница 26: ...SECTION Getting Started 26 ...
Страница 46: ...CHAPTER 2 Initial Switch Configuration Managing System Files 46 ...
Страница 48: ...SECTION Web Configuration 48 ...
Страница 133: ...CHAPTER 4 Configuring the Switch Simple Network Management Protocol 133 Figure 34 SNMP System Configuration ...
Страница 144: ...CHAPTER 4 Configuring the Switch Configuring DHCP Relay and Option 82 Information 144 ...
Страница 184: ...CHAPTER 6 Performing Basic Diagnostics Running Cable Diagnostics 184 ...
Страница 238: ...CHAPTER 12 Port Commands 238 ...
Страница 244: ...CHAPTER 13 Link Aggregation Commands 244 ...
Страница 262: ...CHAPTER 15 RSTP Commands 262 ...
Страница 272: ...CHAPTER 16 IEEE 802 1X Commands 272 ...
Страница 282: ...CHAPTER 17 IGMP Commands 282 ...
Страница 290: ...CHAPTER 18 LLDP Commands 290 ...
Страница 296: ...CHAPTER 19 MAC Commands 296 ...
Страница 306: ...CHAPTER 21 PVLAN Commands 306 ...
Страница 318: ...CHAPTER 22 QoS Commands 318 ...
Страница 352: ...CHAPTER 26 SNMP Commands 352 ...
Страница 355: ...CHAPTER 27 HTTPS Commands 355 EXAMPLE HTTPS redirect enable HTTPS ...
Страница 356: ...CHAPTER 27 HTTPS Commands 356 ...
Страница 362: ...CHAPTER 29 UPnP Commands 362 ...
Страница 370: ...CHAPTER 31 Firmware Commands 370 ...
Страница 372: ...SECTION Appendices 372 ...
Страница 386: ...GLOSSARY 386 ...
Страница 390: ...INDEX 390 W web interface access requirements 49 configuration buttons 50 home page 50 menu list 51 panel display 51 ...
Страница 391: ...INDEX 391 ...
Страница 392: ...149100000079A R01 SMC8028L2 ...