Chapter 40 DHCP
XGS4700-48F User’s Guide
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40.4 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.
40.4.1 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 131
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 XGS4700 Series
Page 2: ......
Page 8: ...Safety Warnings XGS4700 48F User s Guide 8...
Page 24: ...Table of Contents XGS4700 48F User s Guide 24...
Page 25: ...25 PART I User s Guide...
Page 26: ...26...
Page 32: ...Chapter 1 Getting to Know Your Switch XGS4700 48F User s Guide 32...
Page 54: ...Chapter 3 Hardware Overview XGS4700 48F User s Guide 54...
Page 97: ...97 PART II Technical Reference...
Page 98: ...98...
Page 104: ...Chapter 7 System Status and Port Statistics XGS4700 48F User s Guide 104...
Page 118: ...Chapter 8 Basic Setting XGS4700 48F User s Guide 118...
Page 138: ...Chapter 9 VLAN XGS4700 48F User s Guide 138...
Page 142: ...Chapter 10 Static MAC Forward Setup XGS4700 48F User s Guide 142...
Page 174: ...Chapter 14 Bandwidth Control XGS4700 48F User s Guide 174...
Page 188: ...Chapter 17 Link Aggregation XGS4700 48F User s Guide 188...
Page 198: ...Chapter 18 Port Authentication XGS4700 48F User s Guide 198...
Page 216: ...Chapter 21 Policy Rule XGS4700 48F User s Guide 216...
Page 260: ...Chapter 25 AAA XGS4700 48F User s Guide 260...
Page 284: ...Chapter 26 IP Source Guard XGS4700 48F User s Guide 284...
Page 316: ...Chapter 32 Error Disable XGS4700 48F User s Guide 316...
Page 320: ...Chapter 33 Static Route XGS4700 48F User s Guide 320...
Page 328: ...Chapter 35 RIP XGS4700 48F User s Guide 328...
Page 384: ...Chapter 42 ARP Learning XGS4700 48F User s Guide 384...
Page 420: ...Chapter 45 Access Control XGS4700 48F User s Guide 420...
Page 426: ...Chapter 47 Syslog XGS4700 48F User s Guide 426...
Page 434: ...Chapter 48 Cluster Management XGS4700 48F User s Guide 434...
Page 438: ...Chapter 49 MAC Table XGS4700 48F User s Guide 438...
Page 442: ...Chapter 50 IP Table XGS4700 48F User s Guide 442...
Page 446: ...Chapter 52 Routing Table XGS4700 48F User s Guide 446...
Page 454: ...Chapter 54 Troubleshooting XGS4700 48F User s Guide 454...
Page 464: ...Chapter 55 Product Specifications XGS4700 48F User s Guide 464...
Page 473: ...Appendix B Legal Information XGS4700 48F User s Guide 473...
Page 474: ...Appendix B Legal Information XGS4700 48F User s Guide 474...