D-Link DWS-1008 User Manual page 141

DWS-1008 User's Manual
AP Boot Process
A DWL-8220AP access point brings up the link on the AP's port 1 and attempts the boot
process outlined below.
If you want the AP to boot from a specific DWS-1008, you must ensure that only one
DWS-1008 can respond through the AP's port 1 with a high bias under normal operation. If
the boot process fails to locate any DWS-1008, the AP then attempts the boot process on the
AP's port 2.
Note: The steps below describe the network behavior of a Distributed AP when booting. These
steps do not apply to a directly connected AP. The boot process for a directly connected AP
occurs strictly between the AP and switch and makes no use of the network's DHCP or DNS
services.
1. The AP sends a DHCP Discover message from the AP's port 1 to the broadcast address.
2. If a DHCP server is present on the subnet or through a router configured to relay DHCP,
the server replies with a unicast DHCP Offer message. The Offer message must contain
the following parameters:
• IP address for the AP
• IP address of the network's DNS server
• IP address of the subnet's default gateway
Optionally, the Offer message can also contain a list of DWS-1008 IP addresses or hostnames,
in the option 43 field of the DHCP message.
Continuing the DHCP process, the AP broadcasts a DHCP Request to the DHCP servers,
and receives an ACK from a DHCP server. The AP then configures its network connection
with the information contained in the ACK message from that server.
3. The AP sends a Find DWS-1008 message to UDP port 5000 on the subnet broadcast
address.
• The switch that is in the same IP subnet as the AP will receive the message and
respond with a Find DWS-1008 Reply message.
• If the AP is configured as a Distributed AP on a switch and the connection bias
• If the AP is configured as a Distributed AP on a switch but the connection bias
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is high, the switch immediately sends a Find DWS-1008 Reply message.
is low, that switch waits one second, then sends a Find DWS-1008 Reply
message. The delay allows switches with high bias for the AP to respond first.
Configuring DWL-8220AP Access Points
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