I'm having trouble with the interfaces 6 to 10. The most stable config it is with fixed speed to 10m or 100m on the neighbor and does not works always. 1G or auto negotiation fails. Interfaces 1 to 5 works fine. Routers are up to date and I tested 10 of them with the same problem.
Anyone have seen this before?
Any help will be apprecited.
I did not find the right solution from the Internet.