|Question||What changes related to IP Mobility does ArubaOS 6.2 introduce?|
|Why these changes have been implemented?|
|How does these change impact the designing of Mobility Solution?|
|Why is it necessary to have IP routing enabled on user vlan of home agent for IP mobility to work with ArubaOS versions till 6.1.x?|
|Environment||Any ArubaOS Controller running ArubaOS 6.2 or above with IP Mobility configured|
Until ArubaOS 6.1; visitor traffic from Foreign Agent (F) is tunnelled using an IPIP tunnel over to the Home Agent (HA). The IPIP tunnel is a Layer 3 tunnel doesn’t carry the original layer 2 header of the visitor traffic. Hence; the Home Agent wouldn’t be able to identify the VLAN to which the traffic belongs to. The HA routes the client via its own gateway. This also necessitates that the User VLAN on HA for the Visitor must have IP routing enabled.
In ArubaOS 6.2; Layer 2 GRE tunnel is used instead of IPIP (Layer 3 tunnel). By using a Layer 2 tunnel; the Layer 2 header of the visitor can be forwarded by the FA to the HA who can use the information to bridge the traffic on the right VLAN to client’s own default gateway. As this approach bridges the user traffic; we wouldn’t need to have IP routing enabled on the User VLAN.