The link-type point-to-point is for swtich links (non-portfast) and works within the constraints of PVST (recommended for Rapid-PVST).
There's also the concept of "portfast trunk".
Anyway, with point-to-point as a link-type, that has to do with negotiation in the case where one side becomes designated (kinda has to happen anyway) that they will negotiate a quicker jump to forwarding state!
To further elaborate on Scott's explanation:
RSTP can only achieve rapid transition to the forwarding state on edge ports and on point-to-point links. The link type is automatically derived from the duplex mode of a port. A port that operates in full-duplex is assumed to be point-to-point, while a half-duplex port is considered as a shared port by default. This automatic link type setting can be overridden by explicit configuration. In switched networks today, most links operate in full-duplex mode and are treated as point-to-point links by RSTP. This makes them candidates for rapid transition to the forwarding state. "
Als0, here is a nice article on duplex issues! (mismatches etc.) Just thought that I would share since the two are kind of related!
Just what I was looking for!
I couldn't help but feel abit lost reading chapter two of ICND2 (STP, RSTP, PVSTP etc.), I found the concept to be .... well, relatively simple in the beginning but as the book continued through the examplse/explainations it confused me more.
I'm going to take a look at that whitepaper, can anyone suggest other sources for grasping STP/RSTP ?
I'll give the book a read a few times anyway so that I have some chance of absorbing it all.