On 2/16/2012 8:30 PM, Carsten Bormann wrote:
On Feb 16, 2012, at 18:08, Jack Bates wrote:
It at first started with trying to explain that vlan based switching is not
Layer-3. :(
Ah, one of the greatest misconceptions still around in 2012:
-- OSI Layer numbers mean something.
or
-- Somewhere in the sky, there is an exact definition of what is layer 2, layer
3, layer 4, layer 5 (!), layer 7
or
-- my definition is righter than yours
At the same time, it's shocking how many network people I come across
with no real grasp of even what OSI means by each layer, even if it's
only in theory. Just having a grasp of that makes all the world of
difference when it comes to troubleshooting. Start at layer 1 and work
upwards (unless you're able to make appropriate intuitive leaps.) Is it
physically connected? Are the link lights flashing? Can traffic route to
it, etc. etc.
Paul
