Dhcp Relay - TP-Link T1700X-16TS User Manual

Next Hop:
Distance:
Metric:
Interface Name:
9.4

DHCP Relay

Application Environment of DHCP Relay

In DHCP model, DHCP clients broadcast its DHCP request, so the DHCP sever and clients must
be on the same subnet, which require the DHCP server is available in every subnet. It is costly to
build so much DHCP Server. DHCP relay agent solves the problem. Via a relay agent, DHCP
clients request an IP address from the DHCP server in another subnet, and DHCP clients in
different subnets can share the same DHCP server in the internet.
Details of DHCP Relay

A typical application of the switch working at DHCP Relay function is shown below. It can be
altered to meet the network requirement.
To allow all clients in different VLAN request IP address from one server successfully, the DHCP
Relay function can transmit the DHCP packet between clients and server in different VLANs, and
all clients in different VLANs can share one DHCP Server.
When receiving DHCP-DISCOVER and DHCP-REQUEST packets, the switch will fill the

giaddr field with the interface IP of the receiving port, optionally insert the option 82
information, and then forward the packet to the server.
Displays the IPv6 address to which the packet should be sent
next.
Displays the distance metric of route. The smaller the distance,
the higher the priority.
Displays the metric of the route.
Displays the name of the VLAN interface.
Figure 9-9 DHCP Relay Application
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