[Rstplib-users] BPDU issues with RSTPD and rstplib

[Lars T. S. <lt...@da...>]

Hello.

have been battling with the https://github.com/shemminger/RSTP
implementation for a long time, and
trying to make it work with an external switch using the linux DSA
framework. 

Most of my problems is with regards to the convergence time, because my
switches seem to end up using normal STP timers in certain situations.
In addition to this, strange stuff seem to happen when connecting my
units to other "proven to work" switches. 

This leads me to think there is something fishy going on with the BPDUs
to/from my implementation of RSTPD.

For testing, i am using 2 switches with redundant connections. In other
words, SW1 port 1 is connected to SW2 port 1, and port 2 -> port 2.

I output every rx BPDU and tx BPDU on both sides.

When the topology is stable, the root bridge will have both its ports
designated and forwarding. The "slave" port 2 is Root Forwarding, and
port 1 is Alternate discarding. That seems OK. 

However, the BPDU flags coming every hello time is 0x7e. In other words,
every bit except TC bits are set.. 

The "slave" outputs flags 0x78 constantly on its root port. in other
words agreement, forwarding,learning bits are set. 

Does this make any sense? I was under the impression that atleast the
proposal/agreement flags was used only when a convergece was taking
place..

Any help is appreciated.

LT