Are newer DLP Endpoint Agents backwards compatibile with older Enforce and Endpoint Servers?
Are Endpoint agents backwards compatible?
Enforce with Endpoint Prevent/Discover
In some cases, Agents can be patched with hotfix builds that fix issues that are not part of the server build.
Broadcom strongly recommends all customers apply the latest Maintenance Packs on both Server and Agents.
Regarding major version differences, Enforce and Endpoint servers should be upgraded ahead of agents.
Maintenance Packs (on the same major/minor version as Enforce+Endpoint), can be applied to agents before or after upgrading DLP servers.
Detailed definitions of Maintenance Packs, and Agent compatibility with Servers, is given in this KB:
Maintenance Packs for Symantec Data Loss Prevention, and Descriptions of Release Types (broadcom.com)
For moreinformation about this topic, see the section entitled "Backwards compatibility for agent upgrades", in the Symantec DLP Upgrade Guides:
16.0 Help Topic: Backward Compatibility for Agent Upgrades (broadcom.com)