Cisco Cisco Aironet 350 Mini-PCI Wireless LAN Client Adapter Guia Do Desenho
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Enterprise Mobility 4.1 Design Guide
OL-14435-01
Chapter 12 Cisco Unified Wireless and Mobile IP
Roaming on a Mobile IP-enabled Network
Figure 12-6
Example of Mobile IP Function Position in the Microsoft Operating System
The mobile IP client controls that interface with host-originated packets are transmitted by:
•
Installing a new virtual interface adapter at install time.
•
Modifying the host forwarding table.
This virtual adapter looks like any physical adapter to the host (see the example in
). When the adapter is enabled, the
Mobile IP Client modifies the forwarding table to give the virtual adapter the best metric, and the
Windows operating system forwards host-originated packets to the virtual adapter. This allows the
Mobile IP Client to hide the true interface used to transmit the packet and to modify the host’s
forwarding behavior. In the example, there are three interfaces:
Windows operating system forwards host-originated packets to the virtual adapter. This allows the
Mobile IP Client to hide the true interface used to transmit the packet and to modify the host’s
forwarding behavior. In the example, there are three interfaces:
•
A local area connection with a static IP address and no gateway.
•
A Mobile IP Client interface with a configured home address and gateway.
•
A wireless connection that has an address filled in by Mobile IP as 0.0.0.0. The actual address is not
shown to the Windows operating system.
shown to the Windows operating system.
Note that the Mobile IP Client has manipulated the host’s forwarding table so that the lower metric
interface is the Mobile IP Client’s interface. The higher metric routes can be safely ignored when looking
at the table. The real DHCP IP address on the wireless interface is 10.20.41.12. Any route with a
destination address to this gateway has had its metric raised and the default gateway is via the virtual
interface “Ethernet Adapter MIPDRV in Configuration 1.”
interface is the Mobile IP Client’s interface. The higher metric routes can be safely ignored when looking
at the table. The real DHCP IP address on the wireless interface is 10.20.41.12. Any route with a
destination address to this gateway has had its metric raised and the default gateway is via the virtual
interface “Ethernet Adapter MIPDRV in Configuration 1.”
153859
Applications
Operating Systems
(e.g., Windows 2000)
OS NIC
Driver
802.11 NIC
1xRTT NIC
Constant IP
address
TCP/IP protocol stack
VPN client
Mobile IP client
OS NIC
Driver