in the text (doyle, routing tcpip vol1) the beginning graphic and end graphic are shown between the computation... removing the text between as below gives you a chance to really figure it out... router ra is performing the calculation, hence from router ra's perspective... consider ra root or 0...
Link costs are calculated for the outgoing direction from an interface and do not necessarily have to be the same at all interfaces on a link.
before
after
remember, the shortest path remains, and is based on the outgoing link cost...ra's shortest path to rg is through re not rd... the cost is cumulative from ra, so through rd it is 9, through re it is 5...it works... do it yourself for the rest...
wow...
and here is he who paths shortest, himself... he died in 2002..
No comments:
Post a Comment