MPLS

Hello,

Can someone please clarify why do we need a special MPLS patch for iptables to actually "see" the packet properly? I mean iptables is a layer above L2 and MPLS operates at Layer 2.5 & therefore the difference between an MPLS frame and another ethernet frame should be of no concern at the ip layer to iptables or for that matter any application operating at L3.

Please guide.

Regards,