[c-nsp] autonegotiation fail

[Horváth Szabolcs]

Hello!

We have many switches in our network: 2912MfXL, 2924CXLv, 2924MXL, 2924XLv,
295024, 295024C, 3548XL, wsc1900LiteFx. The software versions are very
heterogenous.

We observed that in some cases the autonegotiation between Cisco Catalyst
switches failed. For example: 

We did the measures with iperf (dast.nlanr.net/Projects/Iperf/).
The results: 
	individual test: ~85 Mbit/s up, ~85 Mbit/s down
	bidirectional test: ~80 Mbit/s up, ~7 Mbit/s down(!)

So we set the link to 100 Mbit/full duplex by manually.
The results:
	bidirectional test: ~85 Mbit/s up, ~85 Mbit/s down(!)

We want to force every switch-switch connection to 100 Mbit/full duplex.

What do you suggest?
What are the common pitfalls in this situation?

Thanks for your reply,
Szabolcs Horvath