Before you choose whether to preserve or migrate your Version 5 gateways, you should be aware of the context and restrictions that are described in Coexistence: Preserve or migrate a Version 5 gateway.
Because a WebSphere Application Server Network Deployment Version 6 cell can contain both Version 5 and Version 6 application servers, you can continue to use Version 5 gateways that are running on Version 5 application servers even if you migrate the cell from Version 5 to Version 6. However when you migrate a cell, any previously configured gateway on any Version 5 application server in the cell is replaced with an empty gateway. Therefore you must preserve your Version 5 gateway configurations before you migrate the cell.
To preserve Version 5 gateways and application servers when migrating a Version 5 cell to Version 6, complete the following steps. For information on how to save and restore the Version 5 gateway configurations, see "Preserving an existing gateway configuration" in the WebSphere Application Server Version 5 information center.