Config DHCP service on AIRONET 1040 autonomous

Question

Hello,
I tried to configure DHCP service that will supply addresses for the wifi users.
I configured:
ip dhcp pool sefi
   network 192.168.42.0 255.255.255.0
   dns-server 8.8.8.8
   default-router 192.168.42.1
How can I connect this DHCP service to the Dot11Radio0 interface or to the dot11 SSID??
Thanks

Answer 1

 Configuring DHCP
WLANs can be configured to use the same or different Dynamic Host Configuration Protocol (DHCP) servers or no DHCP server. Two types of DHCP servers are available: internal and external.
Internal DHCP Server
The controllers contain an internal DHCP server. This server is typically used in branch offices that do not already have a DHCP server. The wireless network generally contains 10 access points or fewer, with the access points on the same IP subnet as the controller. The internal server provides DHCP addresses to wireless clients, direct-connect access points, appliance-mode access points on the management interface, and DHCP requests that are relayed from access points. Only lightweight access points are supported. When you want to use the internal DHCP server, you must set the management interface IP address of the controller as the DHCP server IP address.
DHCP option 43 is not supported on the internal server. Therefore, the access point must use an alternative method to locate the management interface IP address of the controller, such as local subnet broadcast, DNS, priming, or over-the-air discovery.
Note See the Chapter 8 "Controlling Lightweight Access Points," or the Controller Deployment Guide at this URL for more information on how access points find controllers:
http://www.cisco.com/en/US/products/ps6366/prod_technical_reference_list.html
Note A internal DHCP server pool will only serve the wireless clients of that controller, not clients of other controllers. Also, internal DHCP server can only serve wireless clients and not wired clients.
Note DHCP required state can cause traffic to not be forwarded properly if a client is deauthenticated or removed. To overcome this, ensure that DHCP required state is always in disabled state.
External DHCP Servers
The operating system is designed to appear as a DHCP Relay to the network and as a DHCP server to clients with industry-standard external DHCP servers that support DHCP Relay, which means that each controller appears as a DHCP Relay agent to the DHCP server and as a DHCP server at the virtual IP address to wireless clients.
Because the controller captures the client IP address obtained from a DHCP server, it maintains the same IP address for that client during intra-controller, inter-controller, and inter-subnet client roaming.
DHCP Assignment
You can configure DHCP on a per-interface or per-WLAN basis. The preferred method is to use the primary DHCP server address assigned to a particular interface.
Per-Interface Assignment
You can assign DHCP servers for individual interfaces. The management interface, AP-manager interface, and dynamic interfaces can be configured for a primary and secondary DHCP server, and the service-port interface can be configured to enable or disable DHCP servers.
Note See the Chapter 10 "Managing Controller Software and Configurations," for information on configuring the controller's interfaces.
Per-WLAN Assignment
You can also define a DHCP server on a WLAN. This server will override the DHCP server address on the interface assigned to the WLAN.
Security Considerations
For enhanced security, we recommend that you require all clients to obtain their IP addresses from a DHCP server. To enforce this requirement, all WLANs can be configured with a DHCP Addr. Assignment Required setting, which disallows client static IP addresses. If DHCP Addr. Assignment Required is selected, clients must obtain an IP address via DHCP. Any client with a static IP address is not be allowed on the network. The controller monitors DHCP traffic because it acts as a DHCP proxy for the clients.
Note WLANs that support management over wireless must allow management (device-servicing) clients to obtain an IP address from a DHCP server. See the "Using Management over Wireless" section for instructions on configuring management over wireless.
If slightly less security is tolerable, you can create WLANs with DHCP Addr. Assignment Required disabled. Clients then have the option of using a static IP address or obtaining an IP address from a designated DHCP server.
Note DHCP Addr. Assignment Required is not supported for wired guest LANs.
You are also allowed to create separate WLANs with DHCP Addr. Assignment Required disabled; then define the primary / secondary DHCP server as 0.0.0.0 on the interface assigned to the WLAN. These WLANs drop all DHCP requests and force clients to use a static IP address. Note that these WLANs do not support management over wireless connections.
Note See Chapter 4 "Configuring Controller Settings," for instructions on globally configuring DHCP proxy.
Note If you want to specify a static IP address for an access point rather than having one assigned automatically by a DHCP server, see the "Configuring a Static IP Address on a Lightweight Access Point" section for more information.
This section provides both GUI and CLI instructions for configuring DHCP.
Using the GUI to Configure DHCP
To configure DHCP using the GUI, follow these steps:
Step 1 Follow the instructions in the "Using the GUI to Configure the Management, AP-Manager, Virtual, and Service-Port Interfaces" section or "Using the GUI to Configure Dynamic Interfaces" section to configure a primary DHCP server for a management, AP-manager, or dynamic interface that will be assigned to the WLAN.
Note When you want to use the internal DHCP server, you must set the management interface IP address of the controller as the DHCP server IP address.
Step 2 Choose WLANs to open the WLANs page.
Step 3 Click the ID number of the WLAN for which you wish to assign an interface. The WLANs > Edit (General) page appears.
Step 4 On the General tab, unselect the Status check box and click Apply to disable the WLAN.
Step 5 Re-click the ID number of the WLAN.
Step 6 On the General tab, choose the interface for which you configured a primary DHCP server to be used with this WLAN from the Interface drop-down list.
Step 7 Choose the Advanced tab to open the WLANs > Edit (Advanced) page.
Step 8 If you want to define a DHCP server on the WLAN that will override the DHCP server address on the interface assigned to the WLAN, select the DHCP Server Override check box and enter the IP address of the desired DHCP server in the DHCP Server IP Addr text box. The default value for the check box is disabled.
Note The preferred method for configuring DHCP is to use the primary DHCP address assigned to a particular interface instead of the DHCP server override.
Note DHCP Server override is applicable only for the default group.
Step 9 If you want to require all clients to obtain their IP addresses from a DHCP server, select the DHCP Addr. Assignment Required check box. When this feature is enabled, any client with a static IP address is not allowed on the network. The default value is disabled.
Note DHCP Addr. Assignment Required is not supported for wired guest LANs.
Step 10 Click Apply to commit your changes.
Step 11 On the General tab, select the Status check box and click Apply to reenable the WLAN.
Step 12 Click Save Configuration to save your changes.
Using the CLI to Configure DHCP
To configure DHCP using the CLI, follow these steps:
Step 1 Follow the instructions in the "Using the GUI to Configure the Management, AP-Manager, Virtual, and Service-Port Interfaces" section or "Using the GUI to Configure Dynamic Interfaces" section to configure a primary DHCP server for a management, AP-manager, or dynamic interface that will be assigned to the WLAN.
Step 2 Disable the WLAN by entering this command:
config wlan disable wlan_id
Step 3 Specify the interface for which you configured a primary DHCP server to be used with this WLAN by entering this command:
config wlan interface wlan_id interface_name
Step 4 If you want to define a DHCP server on the WLAN that will override the DHCP server address on the interface assigned to the WLAN, enter this command:
config wlan dhcp_server wlan_id dhcp_server_ip_address
Note The preferred method for configuring DHCP is to use the primary DHCP address assigned to a particular interface instead of the DHCP server override. If you enable the override, you can use the show wlan command to verify that the DHCP server has been assigned to the WLAN.
Step 5 Reenable the WLAN by entering this command:
config wlan enable wlan_id