D-Link Web Smart Switch User Manual
Advanced
“Advanced” -> “DHCP Relay”
->
“DHCP Relay Agent”
->”
DHCP Relay
Hops Count Limit”
allows the maximum number of hops (routers) that the
DHCP messages can be relayed through to be set. If a packet’s hop count is
more than the hop count limit, the packet is dropped. The range is between 1
and 16hops.
If enable
” DHCP Relay Option 82”
, the relay agent will insert and remove
DHCP relay information (option 82 field) in messages between DHCP servers and
clients. When the relay agent receives the DHCP request, it adds the option 82
information and the IP address of the relay agent to the packet, and then it is
sent on to the DHCP server. When the DHCP server (option 82 capable) receives
the packet, it can implement policies like restricting the number of IP addresses
that can be assigned to a single remote ID or circuit ID. Then the DHCP server
echoes the option 82 field in the DHCP reply. Finally, the relay agent removes
the option 82 field and forwards the packet to the switch port that connects to
the DHCP client that sent the DHCP request.
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