According to VMware support for vSphere 5.5, ESXi 5.5, and vCenter Server 5.5 will be ending on September 19th, 2018. We are recommending you upgrade your VM server hosts to the highest supported version available.
“The End of General Support for vSphere 5.5 is September 19, 2018. To maintain your full level of support and subscription services, VMware recommends upgrading to vSphere 6.5, or to a newer version. VMware has extended the general support for vSphere 6.5 to a full five years from date of release, which means the general support for vSphere 6.5 will end November 15, 2021. For more information on the benefits of upgrading and how to upgrade, visit the VMware vSphere Upgrade Center.
If you would like assistance in moving to a newer version of vSphere, VMware’s vSphere Upgrade Service is available. This service delivers a comprehensive guide to upgrading your virtual infrastructure. It includes recommendations for planning and testing the upgrade, the actual upgrade itself, validation guidance and rollback procedures. For more information contact your Technical Account Manager or visit VMware Professional Services and VMware Consulting Engagement Request.
In the event you are unable to upgrade before the End of General Support (EOGS) and are active on Support and Subscription, you have the option to purchase extended support in one year increments for up to two years beyond the EOGS date. Visit VMware Extended Support for more information.
Technical Guidance for vSphere 5.5 is available until September 19, 2020 primarily through the self-help portal. During the Technical Guidance phase, VMware does not offer new hardware support, server/client/guest OS updates, new security patches or bug fixes unless otherwise noted. For more information, visit VMware Lifecycle Support Phases.”