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Chapter 29 DHCP
GS2200-48 User’s Guide
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29.4 DHCP Relay
Configure DHCP relay on the Switch if the DHCP clients and the DHCP server are
not in the same broadcast domain. During the initial IP address leasing, the
Switch helps to relay network information (such as the IP address and subnet
mask) between a DHCP client and a DHCP server. Once the DHCP client obtains an
IP address and can connect to the network, network information renewal is done
between the DHCP client and the DHCP server without the help of the Switch.
The Switch can be configured as a global DHCP relay. This means that the Switch
forwards all DHCP requests from all domains to the same DHCP server. You can
also configure the Switch to relay DHCP information based on the VLAN
membership of the DHCP clients.
29.4.1 DHCP Relay Agent Information
The Switch can add information about the source of client DHCP requests that it
relays to a DHCP server by adding Relay Agent Information. This helps provide
authentication about the source of the requests. The DHCP server can then
provide an IP address based on this information. Please refer to RFC 3046 for
more details.
The DHCP Relay Agent Information feature adds an Agent Information field to
the Option 82 field. The Option 82 field is in the DHCP headers of client DHCP
request frames that the Switch relays to a DHCP server.
Relay Agent Information can include the System Name of the Switch if you
select this option. You can change the System Name in Basic Settings >
General Setup.
The following describes the DHCP relay information that the Switch sends to the
DHCP server:
Table 91
Relay Agent Information
FIELD LABELS
DESCRIPTION
Slot ID
(1 byte) This value is always 0 for stand-alone
switches.
Port ID
(1 byte) This is the port that the DHCP client is
connected to.
VLAN ID
(2 bytes) This is the VLAN that the port belongs to.
Information
(up to 64 bytes) This optional, read-only field is set
according to system name set in Basic Settings >
General Setup.
Summary of Contents for GS2200-48
Page 2: ......
Page 8: ...Safety Warnings GS2200 48 User s Guide 8 ...
Page 22: ...22 ...
Page 28: ...Chapter 1 Getting to Know Your Switch GS2200 48 User s Guide 28 ...
Page 32: ...Chapter 2 Hardware Installation and Connection GS2200 48 User s Guide 32 ...
Page 40: ...40 ...
Page 62: ...Chapter 6 System Status and Port Statistics GS2200 48 User s Guide 62 ...
Page 76: ...Chapter 7 Basic Setting GS2200 48 User s Guide 76 ...
Page 78: ...78 ...
Page 102: ...Chapter 9 Static MAC Forward Setup GS2200 48 User s Guide 102 ...
Page 122: ...Chapter 11 Spanning Tree Protocol GS2200 48 User s Guide 122 ...
Page 126: ...Chapter 12 Bandwidth Control GS2200 48 User s Guide 126 ...
Page 148: ...Chapter 17 Port Security GS2200 48 User s Guide 148 ...
Page 156: ...Chapter 18 Classifier GS2200 48 User s Guide 156 ...
Page 164: ...Chapter 19 Policy Rule GS2200 48 User s Guide 164 ...
Page 214: ...Chapter 24 IP Source Guard GS2200 48 User s Guide 214 Figure 98 DHCP Snooping ...
Page 236: ...236 ...
Page 270: ...270 ...
Page 278: ...Chapter 31 Maintenance GS2200 48 User s Guide 278 ...
Page 304: ...Chapter 34 Syslog GS2200 48 User s Guide 304 ...
Page 312: ...Chapter 35 Cluster Management GS2200 48 User s Guide 312 ...
Page 316: ...Chapter 36 MAC Table GS2200 48 User s Guide 316 ...
Page 320: ...Chapter 37 IP Table GS2200 48 User s Guide 320 ...
Page 324: ...Chapter 39 Routing Table GS2200 48 User s Guide 324 ...
Page 327: ...327 PART VI Product Specifications Product Specifications 329 ...
Page 328: ...328 ...
Page 336: ...Chapter 41 Product Specifications GS2200 48 User s Guide 336 ...
Page 338: ...338 ...
Page 352: ...Appendix B Legal Information GS2200 48 User s Guide 352 ...
Page 362: ...Index GS2200 48 User s Guide 362 ...