I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. Summary: ready This document deals with fragmentation issues in the General Routing Encapsulation (GRE). Fragmentation naturally presents potential denial of service and resource exhaustion vulnerabilities. I think the Security Considerations section of this document adequately addresses these potential vulnerabilities.