> On Feb 28, 2022, at 8:00 PM, Dino Farinacci <farina...@gmail.com> wrote: > >> There is a base case to the recursion, i.e., where logical information meets >> fermions and bosons (literally). But that tells you only that base layer; it >> tells you nothing about the meaning of the headers you see inside, e.g., in >> OSI, they would be 1,2,3,4,5,6,7, but in an IP tunnel, they could be >> 1,2,3,3,4,5,6,7, with GRE they could be 1,2,3,2,3,4,5,6,7, etc. > > An IP tunnel with protocol number 4 is indeed 1,2,3,3,4,5,6,7, but LISP (UDP > port 4341) UDP tunnels are 1,2,3,4,3,4,5,6,7 and GRE is 1,2,3,3,4,5,6,7 > because it runs directly over IP with protocol number 47. > > Dino
If GRE runs over IP, then it would be the same as IP-over-UDP tunnels: 1,2,3(IP), 4(GRE, since it is a protocol number of IP), 3(IP in GRE), 5,6,7, i.e.: 1,2,3,4,3,4,5,6,7 It’s all actually relative, though - to the left IP, GRE is layer 4. To the right IP, GRE is layer 2. Joe _______________________________________________ Int-area mailing list Int-area@ietf.org https://www.ietf.org/mailman/listinfo/int-area
