AT&T Cisco Systems AT&T Labs Cisco Systems This document imposes a new requirement on Label Edge Routers (LER) specifying that when determining whether to MPLS encapsulate an IP packet, the determination is made independent of any IP options that may be carried in the IP packet header. Lack of a formal standard may result in a different forwarding behavior for different IP packets associated with the same prefix-based Forwarding Equivalence Class (FEC). While an IP packet with either a specific option type or no header option may follow the MPLS label switched path (LSP) associated with a prefix-based FEC, an IP packet with a different option type but associated with the same prefix-based FEC may bypass MPLS encapsulation and instead be IP routed downstream. IP option packets that fail to be MPLS encapsulated simply due to their header options present a security risk against the MPLS infrastructure.