RAPID-PVST+ Changing the link to P2P, but still waits 2 x FD

From: Hobbs (deadheadblues@gmail.com)
Date: Wed Dec 10 2008 - 16:31:58 ARST

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Hello,

SW3 f0/3 ------e0/1 R3

Rapid-PVST+ detects this link as shared since it is half-duplex.
This causes RSTP to wait 2 x forward-delay before forwarding (when this port
is enabled).
In order to have it forward immediately once it becomes DESIGNATED I change
the link type to P2P.

However this didn't seem to work ( I am using a forward delay of 5 seconds
to speed it up):

SW3#show run | inc pvst
spanning-tree mode rapid-pvst

SW3#debug spanning-tree events
Spanning Tree event debugging is on

SW3#conf t
SW3(config)#int f0/3
SW3(config-if)#shut
SW3(config-if)#spanning-tree link-type point-to-point
SW3(config-if)#no shut
SW3(config-if)#^Z

02:00:00: RSTP(1): initializing port Fa0/3
02:00:00: RSTP(1): Fa0/3 is now designated <---- NOW IT SHOULD
FORWARD
02:00:00: RSTP(1): transmitting a proposal on Fa0/3

SW3#show spanning-tree | inc 0/3
Fa0/3 Desg BLK 100 128.3 P2p <---- STILL
BLOCKING (BUT ITS "DESG" ROLE)

02:00:02: RSTP(1): transmitting a proposal on Fa0/3
02:00:04: RSTP(1): transmitting a proposal on Fa0/3
02:00:05: RSTP(1): Fa0/3 fdwhile Expired
02:00:06: RSTP(1): transmitting a proposal on Fa0/3
02:00:08: RSTP(1): transmitting a proposal on Fa0/3
02:00:10: RSTP(1): transmitting a proposal on Fa0/3
02:00:10: RSTP(1): Fa0/3 fdwhile Expired

SW3#show spanning-tree | inc 0/3
Fa0/3 Desg FWD 100 128.3 P2p <---- NOW IT'S
FORWARDING
SW3#

This is from the DocCD:

spanning-tree link-type point-to-point
(Recommended for rapid-PVST+ mode only) Specify that the link type for this
port is point-to-point.
If you connect this port (local port) to a remote port through a
point-to-point link and the local port becomes a designated port, the switch
negotiates with the remote port and rapidly changes the local port to the
forwarding state.

Am I testing this wrong? AM I misunderstanding what the DocCD says?
I have also tried this with a switch to switch connection on another port,
and it still waits 2 x FD.

thanks,

Blogs and organic groups at http://www.ccie.net

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