Configure internal DHCP server | DHCP for WLANs | Cisco Catalyst 9800 Series Wireless Controller Software Configuration Guide, Cisco IOS XE 26.x

Provides instructions for configuring an internal DHCP server to automatically assign IP addresses to wireless clients. It includes steps for adjusting DHCP settings within a wireless policy profile using both the web interface and CLI commands. The configuration covers setting up centralized DHCP services, defining network pools, exclusions, and static IP reservations. Additionally, it outlines commands for verifying the DHCP configuration, including client binding checks and analyzing DHCP relay and packet punt statistics.

Configure the internal DHCP server under client VLAN SVI (GUI)

This task configures the internal DHCP server settings for a client VLAN Switched Virtual Interface (SVI) to enable DHCP relay functionality.

Use this procedure when you need to set up DHCP relay on an SVI to forward DHCP requests to a designated helper address. This configuration is typically performed on network switches to enable DHCP services across VLANs.

Procedure

Choose Configuration > Layer2 > VLAN > SVI.
Click an SVI.
Click the Advanced tab.
Under DHCP Relay settings, enter the IPV4 Helper Address.
Click Update & Apply to Device.

The internal DHCP server is configured under the client VLAN SVI with the specified helper address, enabling DHCP relay functionality for the selected SVI.

Configure the internal DHCP server under client VLAN SVI (CLI)

Set up an internal DHCP server to provide IP address assignment for wireless and wired clients through the client VLAN SVI configuration.

The internal DHCP server can be configured under the client VLAN SVI to serve both wireless and wired clients. This configuration requires proper IP addressing and helper configuration to function correctly with the wireless infrastructure.

Before you begin

For wireless clients, only two DHCP servers are supported.
To use the internal DHCP server for both wireless and wired client VLAN, an IP address must be configured under the client VLAN SVI.
For wireless clients, the IP address of the internal DHCP server must be different from the address of the wireless client VLAN SVI (in the DHCP helper address configuration).
For wireless clients, the internal DHCP server can be configured under the client VLAN SVI or under the wireless policy profile.

Procedure

Enter global configuration mode.
Example:
```
Device# configure terminal
```

Create a loopback interface and enter interface configuration mode.

Example:

Device(config)# interface loopback interface-number

Example:

Device(config)# interface Loopback0

Configure the IP address for the interface.

Example:

Device(config-if)# ip address ip-address subnet-mask

Example:

Device(config-if)# ip address 10.10.10.1 255.255.255.255

Exit interface configuration mode.
Example:
```
Device(config-if)# exit
```

Configure the VLAN ID.

Example:

Device(config)# interface vlan vlan-id

Example:

Device(config)# interface vlan 32

Configure the IP address for the interface.

Example:

Device(config-if)# ip address ip-address subnet-mask

Example:

Device(config-if)# ip address 192.168.32.100 255.255.255.0

Configure the destination address for UDP broadcasts.
Example:
```
Device(config-if)# ip helper-address ip-address
```
Example:
```
Device(config-if)# ip helper-address 10.10.10.1
```
Note

If the IP address used in the IP helper-address command is an internal address of the controller an internal DHCP server is used. Otherwise, the external DHCP server is used.
Disable the Maintenance Operation Protocol (MOP) for an interface.
Example:
```
Device(config-if)# no mop enabled
```
Disable the task of sending MOP periodic system ID messages.
Example:
```
Device(config-if)# no mop sysid
```
Exit interface configuration mode.
Example:
```
Device(config-if)# exit
```

Specify the IP address that the DHCP server should not assign to DHCP clients.

Example:

Device(config)# ip dhcp excluded-address ip-address

Example:

Device(config)# ip dhcp excluded-address 192.168.32.1

Specify the IP addresses that the DHCP server should not assign to DHCP clients.

Example:

Device(config)# ip dhcp excluded-address ip-address

Example:

Device(config)# ip dhcp excluded-address 192.168.32.100

Configure the DHCP pool address.

Example:

Device(config)# ip dhcp pool pool-name

Example:

Device(config)# ip dhcp pool pool-vlan32

Specify the network number in dotted-decimal notation, along with the mask address.

Example:

Device(dhcp-config)# network network-address subnet-mask

Example:

Device(dhcp-config)# network 192.168.32.0 255.255.255.0

Specify the IP address of the default router for a DHCP client.

Example:

Device(dhcp-config)# default-router ip-address

Example:

Device(dhcp-config)# default-router 192.168.32.1

Exit DHCP configuration mode.
Example:
```
Device(dhcp-config)# exit
```

Configure the WLAN policy profile and enter wireless policy configuration mode.

Example:

Device(config)# wireless profile policy profile-policy

Example:

Device(config)# wireless profile policy default-policy-profile

Configure central association for locally switched clients.
Example:
```
Device(config-wireless-policy)# central association
```
Configure the central DHCP for locally switched clients.
Example:
```
Device(config-wireless-policy)# central dhcp
```

Configure WLAN for central switching.

Example:

Device(config-wireless-policy)# central switching

Add a description for the policy profile.

Example:

Device(config-wireless-policy)# description "policy-profile-description"

Example:

Device(config-wireless-policy)# description "default policy profile"

Assign the profile policy to the VLAN.

Example:

Device(config-wireless-policy)# vlan vlan-id

Example:

Device(config-wireless-policy)# vlan 32

Enable the wireless profile policy.

Example:

Device(config-wireless-policy)# no shutdown

The internal DHCP server is now configured under the client VLAN SVI and can provide IP address assignment to both wireless and wired clients connected to the specified VLAN.

Configure the internal DHCP server under a wireless policy profile (GUI)

Configure DHCP settings to enable automatic IP address assignment for wireless clients connected to the network under a specific policy profile.

Use this procedure when you need to set up internal DHCP server functionality within a wireless policy profile to provide IP address allocation for connected wireless devices.

Procedure

Choose Configuration > Tags & Profiles > Policy.
Click a policy name.
Click the Advanced tab.
Under DHCP settings, check or uncheck the IPv4 DHCP Required check box and enter the DHCP Server IP Address.
Click Update & Apply to Device.

The internal DHCP server is configured under the wireless policy profile and the settings are applied to the device.

Configure the internal DHCP server under a wireless policy profile (CLI)

Enable DHCP services for wireless clients by configuring an internal DHCP server within a wireless policy profile.

The internal DHCP server provides IP address assignment and network configuration to wireless clients. This configuration includes setting up loopback and VLAN interfaces, defining DHCP pools, and associating the DHCP server with a wireless policy profile.

Procedure

Enter global configuration mode.
Example:
```
Device# configure terminal
```

Create a loopback interface and enter interface configuration mode.

Example:

Device(config)# interface loopback interface-number

Example:

Device(config)# interface Loopback0

Configure the IP address for the interface.

Example:

Device(config-if)# ip address ip-address subnet-mask

Example:

Device(config-if)# ip address 10.10.10.1 255.255.255.255

Exit interface configuration mode.
Example:
```
Device(config-if)# exit
```

Configure the VLAN ID.

Example:

Device(config)# interface vlan vlan-id

Example:

Device(config)# interface vlan 32

Configure the IP address for the interface.

Example:

Device(config-if)# ip address ip-address subnet-mask

Example:

Device(config-if)# ip address 192.168.32.100 255.255.255.0

Disable the Maintenance Operation Protocol (MOP) for an interface.
Example:
```
Device(config-if)# no mop enabled
```
Disable the task of sending MOP periodic system ID messages.
Example:
```
Device(config-if)# no mop sysid
```
Exit interface configuration mode.
Example:
```
Device(config-if)# exit
```

Specify the IP address that the DHCP server should not assign to DHCP clients.

Example:

Device(config)# ip dhcp excluded-address ip-address

Example:

Device(config)# ip dhcp excluded-address 192.168.32.100

Configure the DHCP pool address.

Example:

Device(config)# ip dhcp pool pool-name

Example:

Device(config)# ip dhcp pool pool-vlan32

Specify the network number in dotted-decimal notation along with the mask address.

Example:

Device(dhcp-config)# network network-address subnet-mask

Example:

Device(dhcp-config)# network 192.168.32.0 255.255.255.0

Specify the IP address of the default router for a DHCP client.

Example:

Device(dhcp-config)# default-router ip-address

Example:

Device(dhcp-config)# default-router 192.168.32.1

Exit DHCP configuration mode.
Example:
```
Device(dhcp-config)# exit
```

Configure a WLAN policy profile and enter wireless policy configuration mode.

Example:

Device(config)# wireless profile policy profile-policy

Example:

Device(config)# wireless profile policy default-policy-profile

Configure central association for locally switched clients.
Example:
```
Device(config-wireless-policy)# central association
```

Configure local switching.

Example:

Device(config-wireless-policy)# central switching

Add a description for the policy profile.

Example:

Device(config-wireless-policy)# description "policy-profile-name"

Example:

Device(config-wireless-policy)# description "default policy profile"

Enable DHCP Option 82 for the wireless clients.
Example:
```
Device(config-wireless-policy)# ipv4 dhcp opt82
```

Enable ASCII on DHCP Option 82.

Example:

Device(config-wireless-policy)# ipv4 dhcp opt82 ascii

Enable VLAN ID.

Example:

Device(config-wireless-policy)# ipv4 dhcp opt82 format vlan-id

Example:

Device(config-wireless-policy)# ipv4 dhcp opt82 format vlan32

Support the addition of Cisco 2-byte Remote ID (RID) for DHCP Option 82.
Example:
```
Device(config-wireless-policy)# ipv4 dhcp opt82 rid
```

Configure the WLAN's IPv4 DHCP server.

Example:

Device(config-wireless-policy)# ipv4 dhcp server ip-address

Example:

Device(config-wireless-policy)# ipv4 dhcp server 10.10.10.1

Assign the profile policy to the VLAN.

Example:

Device(config-wireless-policy)# vlan vlan-id

Example:

Device(config-wireless-policy)# vlan 32

Enable the wireless profile policy.

Example:

Device(config-wireless-policy)# no shutdown

The internal DHCP server is now configured and operational within the wireless policy profile, ready to provide IP addresses and network configuration to wireless clients.

Configure the internal DHCP server globally (GUI)

Configure a DHCP pool to enable automatic IP address assignment for network devices through the internal DHCP server.

Use this procedure when you need to set up centralized IP address management for your network infrastructure using the GUI interface.

Procedure

Choose Administration > DHCP Pools > Pools.
Click Add.

The Create DHCP Pool window is displayed.
Enter the DHCP Pool Name, Network, Starting IP, and Ending IP.
From the IP Type, Subnet Mask, and Lease drop-down lists, choose a value.
Click the Reserved Only toggle button.
Click Apply to Device.

The DHCP pool is created and applied to the device, enabling automatic IP address assignment within the specified range.

Configure the internal DHCP server globally (CLI)

Enable centralized DHCP services for wireless clients by configuring the internal DHCP server with appropriate network pools and policies.

The internal DHCP server configuration allows the wireless controller to provide IP addresses to wireless clients directly, eliminating the need for external DHCP servers in certain network deployments.

Procedure

Enter global configuration mode.
Example:
```
Device# configure terminal
```

Create a loopback interface and enter interface configuration mode.

Example:

Device(config)# interface loopback interface-number

Example:

Device(config)# interface Loopback0

Configure the IP address for the interface.

Example:

Device(config-if)# ip address ip-address subnet-mask

Example:

Device(config-if)# ip address 10.10.10.1 255.255.255.255

Exit interface configuration mode.
Example:
```
Device(config-if)# exit
```

Configure the VLAN ID.

Example:

Device(config)# interface vlan vlan-id

Example:

Device(config)# interface vlan 32

Configure the IP address for the interface.

Example:

Device(config-if)# ip address ip-address subnet-mask

Example:

Device(config-if)# ip address 192.168.32.100 255.255.255.0

Disable the Maintenance Operation Protocol (MOP) for an interface.
Example:
```
Device(config-if)# no mop enabled
```
Disable the task of sending the MOP periodic system ID messages.
Example:
```
Device(config-if)# no mop sysid
```
Exit the interface configuration mode.
Example:
```
Device(config-if)# exit
```

Specify the target DHCP server parameters.

Example:

Device(config)# ip dhcp-server ip-address

Example:

Device(config)# ip dhcp-server 10.10.10.1

Specify the IP address that the DHCP server should not assign to DHCP clients.

Example:

Device(config)# ip dhcp excluded-address ip-address

Example:

Device(config)# ip dhcp excluded-address 192.168.32.100

Configure the DHCP pool address.

Example:

Device(config)# ip dhcp pool pool-name

Example:

Device(config)# ip dhcp pool pool-vlan32

Specify the network number in dotted-decimal notation along with the mask address.

Example:

Device(dhcp-config)# network network-address subnet-mask

Example:

Device(dhcp-config)# network 192.168.32.0 255.255.255.0

Specify the IP address of the default router for a DHCP client.

Example:

Device(dhcp-config)# default-router ip-address

Example:

Device(dhcp-config)# default-router 192.168.32.1

Exit DHCP configuration mode.
Example:
```
Device(dhcp-config)# exit
```

Configure a WLAN policy profile and enter wireless policy configuration mode.

Example:

Device(config)# wireless profile policy profile-policy

Example:

Device(config)# wireless profile policy default-policy-profile

Configure central association for locally switched clients.
Example:
```
Device(config-wireless-policy)# central association
```
Configure central DHCP for locally switched clients.
Example:
```
Device(config-wireless-policy)# central dhcp
```

Configure local switching.

Example:

Device(config-wireless-policy)# central switching

Add a description for the policy profile.

Example:

Device(config-wireless-policy)# description policy-profile-description

Example:

Device(config-wireless-policy)# description "default policy profile"

Assign the profile policy to the VLAN.

Example:

Device(config-wireless-policy)# vlan vlan-id

Example:

Device(config-wireless-policy)# vlan 32

Enable the profile policy.

Example:

Device(config-wireless-policy)# no shutdown

The internal DHCP server is now configured globally with the specified pool, exclusions, and wireless policy profile settings to serve DHCP requests from wireless clients.

Configure IP reservations in the internal DHCP server (CLI)

Reserve specific IP addresses for clients in the internal DHCP server to ensure consistent address assignment.

IP reservations allow DHCP servers to assign the same IP address to specific clients based on their client ID or MAC address. This is useful for servers, printers, or other devices that require consistent network addressing.

Procedure

Enter global configuration mode.
Example:
```
Device# configure terminal
```

Configure the DHCP pool address.

Example:

Device(config)# ip dhcp pool pool-name

Example:

Device(config)# ip dhcp pool dhcp-pool-add

Specify the network number in dotted-decimal notation along with the mask address.

Example:

Device(dhcp-config)# network network-address mask-address

Example:

Device(dhcp-config)# network 192.168.32.0 255.255.255.0

Configure a reserved address using either the client ID or the MAC address.
Example:
```
Device(dhcp-config)# address ip-address client-id client-id
```
Example:
```
Device(dhcp-config)# address ip-address hardware-address client-mac-id
```
Example:
```
Device(dhcp-config)# address 209.165.200.224 client-id dhcp-client-id
```
Note

The IP reservation is contingent on the type of identifier, be it the client ID or the MAC address that the client provides. If the client sends its DHCP DISCOVER or REQUEST using the client ID, set your IP reservation using the client ID and not the hardware address.

IP reservations are configured in the internal DHCP server, ensuring that specified clients receive consistent IP addresses based on their identifiers.

Verify internal DHCP configuration

Verify internal DHCP configuration using specific show commands to check client binding, DHCP relay statistics for wireless clients, and DHCP packet punt statistics.

Client binding verification

To verify client binding, use this command:

Device# show ip dhcp binding 

Bindings from all pools not associated with VRF:
IP address      Client-ID/              Lease expiration        Type       State      Interface
                Hardware address/
                User name
192.168.32.3    0130.b49e.491a.53       Mar 23 2018 06:42 PM    Automatic  Active     Loopback0

DHCP relay statistics verification

To verify the DHCP relay statistics for a wireless client, use this command:

Device# show wireless dhcp relay statistics 

DHCP Relay Statistics
---------------------

DHCP Server IP :   10.10.10.1

Message              Count
--------------------------
DHCPDISCOVER      :  1
BOOTP FORWARD     :  137
BOOTP REPLY       :  0
DHCPOFFER         :  0
DHCPREQUEST       :  54
DHCPACK           :  0
DHCPNAK           :  0
DHCPDECLINE       :  0
DHCPRELEASE       :  0
DHCPINFORM        :  82

Tx/Rx Time :
------------
LastTxTime : 18:42:18
LastRxTime : 00:00:00

Drop Counter :
-------------
TxDropCount : 0

DHCP packet punt statistics verification

To verify the DHCP packet punt statistics in CPP, use this command:

Device# show platform hardware chassis active qfp feature wireless punt statistics 

CPP Wireless Punt stats:

                                 App Tag     Packet Count
                                 -------     ------------
         CAPWAP_PKT_TYPE_DOT11_PROBE_REQ            14442
              CAPWAP_PKT_TYPE_DOT11_MGMT               50
              CAPWAP_PKT_TYPE_DOT11_IAPP             9447
              CAPWAP_PKT_TYPE_DOT11_RFID                0
               CAPWAP_PKT_TYPE_DOT11_RRM                0
             CAPWAP_PKT_TYPE_DOT11_DOT1X                0
        CAPWAP_PKT_TYPE_CAPWAP_KEEPALIVE             2191
      CAPWAP_PKT_TYPE_MOBILITY_KEEPALIVE                0
            CAPWAP_PKT_TYPE_CAPWAP_CNTRL             7034
             CAPWAP_PKT_TYPE_CAPWAP_DATA                0
          CAPWAP_PKT_TYPE_MOBILITY_CNTRL                0
                         WLS_SMD_WEBAUTH                0
                       SISF_PKT_TYPE_ARP             5292
                      SISF_PKT_TYPE_DHCP              140
                     SISF_PKT_TYPE_DHCP6             1213
                   SISF_PKT_TYPE_IPV6_ND              350
                SISF_PKT_TYPE_DATA_GLEAN               44
             SISF_PKT_TYPE_DATA_GLEAN_V6               51
                SISF_PKT_TYPE_DHCP_RELAY              122
         CAPWAP_PKT_TYPE_CAPWAP_RESERVED                0