Hmmm. Although... Do level 2 routes change much? And are there many
asymmetries in these systems? (ATM,...)
neal
On Mon, 10 May 1999, Stefan Savage wrote:
> Here's a really stupid test for path symmetry.
>
> 1) do a traceroute from A to B, number of hops reported = n
> 2) send a ping from A to B and look at the ttl field, most os's start ttl at
> 64 or 255 (easy to figure out which). Subtract from ttl value.
>
> 3) now take the difference of these two numbers. If the difference is large
> then there are alot more hops in one direction than the other. I've found a
> couple doozies, but generally folks are pretty close. It'd be a one day
> project for someone to built a random tester to measure this though.
>
> - Stefan
>
>