User's Manual

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The 3502P access point uses the type-length-value (TLV) format for DHCP Option 43. DHCP servers
must be programmed to return the option based on the access points DHCP Vendor Class Identifier
(VCI) string (DHCP Option 60). The VCI string for the 3502P access point is:
Cisco AP c3502
The format of the TLV block is listed below:
Type: 0xf1 (decimal 241)
Length: Number of controller IP addresses * 4
Value: List of WLC management interfaces
To configure DHCP Option 43 in the embedded Cisco IOS DHCP server, follow these steps:
Step 1 Enter configuration mode at the Cisco IOS CLI.
Step 2 Create the DHCP pool, including the necessary parameters such as default router and name
server. A DHCP scope example is as follows:
ip dhcp pool <pool name>
network <IP Network> <Netmask>
default-router <Default router>
dns-server <DNS Server>
Where:
<pool name> is the name of the DHCP pool, such as AP3502
<IP Network> is the network IP address where the controller resides, such as
10.0.15.1
<Netmask> is the subnet mask, such as 255.255.255.0
<Default router> is the IP address of the default router, such as 10.0.0.1
<DNS Server> is the IP address of the DNS server, such as 10.0.10.2
Step 3 Add the option 60 line using the following syntax:
option 60 ascii “VCI string
For the VCI string, “Cisco AP c3502”. The quotation marks must be included.
Step 4 Add the option 43 line using the following syntax:
option 43 hex <hex string>
The hex string is assembled by concatenating the TLV values shown below:
Type + Length + Value
Type is always f1(hex). Length is the number of controller management IP addresses times 4
in hex. Value is the IP address of the controller listed sequentially in hex.
ap3502getstart.fm Page 31 Wednesday, December 22, 2010 8:51 AM