some ethernet notes...

the beginning never ends...

key pin outs...

straight through 1-1, 2-2 and 3-3, 6-6
xover                1-3, 2-6 and 3-1, 6-2

straight is easy, crossed; odd to odd, even to even...  with auto- mdix it doesn't matter (automatic medium dependent interface crossover senses tx & rx)

switches detect duplex settings through auto-negotiation using flp (fast link pulses) without auto-negotiation, cisco switches will default to half duplex on 10/100 links, or full for 1000. hard setting the port disables auto-negotiation

for csma/cd here:

http://insearchofthecert.blogspot.com/search/label/csma%2Fcd

icnd2 notes for review, here:

http://insearchofthecert.blogspot.com/search/label/icnd2

forward/filter here:

http://insearchofthecert.blogspot.com/2011/10/forwardfilter-conundrum.html