DHCP Proxy Mode
In DHCP Proxy Mode, the controller’s virtual IP address is used as the source IP address of all DHCP transactions to the client. As a result, the real DHCP server IP address is not exposed in the air. This virtual IP is displayed in debug output for DHCP transactions on the controller. However, use of a virtual IP address can cause issues on certain types of clients.
When multiple offers come from external DHCP servers, the DHCP proxy normally selects the first one that comes in and sets the IP address of the server in the client data structure. As a result, all following transactions go through the same DHCP server until a transaction fails after retries. At this point, the proxy selects a different DHCP server for the client.
DHCP proxy is enabled by default. All controllers in a mobility list must have the same DHCP proxy setting.
Note |
DHCP proxy must be enabled in order for DHCP option 82 to operate correctly. |
Proxy Mode Packet Flow
This section contains the following subsections: