GRE over IPSec, Policy Question

Hey,

So I watched the video at http://gregsowell.com/?p=1290 on setting this ip. I have everything all setup but came up with a question I am hoping someone can answer pretty easily. I haven’t been able to find the answer anywhere on the WIKI or the Forums.

Since the IPSec tunnel will be used to forward only GRE traffic can the protocol for the policy be set to 47 instead of “all”? … Is there any advantage of routing “all” protocols instead of just the GRE tunnel traffic? All of the LAN traffic should be routing through protocol 47 correct? Or is some other protocol also getting used? In the video he just left it as “all”.

-Eric