D-Link DWS-1008 Product Manual - Page 127

Boot Process for Distributed APs, Establishing Connectivity on the Network

Page 127 highlights

Boot Process for Distributed APs When a distributed AP boots on the network, it uses the process described in this section. Note that this process applies only to distributed APs; it does 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. The boot process for a distributed AP consists of the following steps: 1. Establishing connectivity on the network 2. Contacting an DWS-1008 switch 3. Loading and activating an operational image 4. Obtaining configuration information from the switch These steps are described in more detail in the following sections. Establishing Connectivity on the Network When an AP is first powered on, its bootloader obtains an IP address for the AP. The IP address is either obtained through DHCP (the default) or can be statically configured on the AP. How a Distributed AP Obtains an IP Address through DHCP By default, a distributed AP obtains its IP address through DHCP. The AP brings up the link on the AP's port 1 and attempts the boot process outlined below. 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 • Domain name of the network • IP address of the network's DNS server • IP address of the subnet's default router (gateway) Optionally, the DHCP Offer message can also contain a list of DWS-1008 IP addresses or hostnames, in the Option 43 field. 3. 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. D-Link DWS-1008 User Manual 108

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D-Link DWS-1008 User Manual
108
Boot Process for Distributed APs
When a distributed AP boots on the network, it uses the process described in this section. Note that
this process applies only to distributed APs; it does 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.
The boot process for a distributed AP consists of the following steps:
1. Establishing connectivity on the network
2. Contacting an DWS-1008 switch
3. Loading and activating an operational image
4. Obtaining configuration information from the switch These steps are described in more
detail in the following sections.
Establishing Connectivity on the Network
When an AP is first powered on, its bootloader obtains an IP address for the AP. The IP address is either
obtained through DHCP (the default) or can be statically configured on the AP.
How a Distributed AP Obtains an IP Address through DHCP
By default, a distributed AP obtains its IP address through DHCP. The AP brings up the link on the AP’s
port 1 and attempts the boot process outlined below.
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
• Domain name of the network
• IP address of the network’s DNS server
• IP address of the subnet’s default router (gateway)
Optionally, the DHCP Offer message can also contain a list of DWS-1008 IP addresses or
hostnames, in the Option 43 field.
3. 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.