This problem related to my previous topic: https://e2e.ti.com/support/interface/f/138/p/784626/2908885
I added common mode filter into my design, but I still have the same problem.
I have custom board with DP83867IR (48-pin package) and another board with KSZ9896. They both work fine at 1Gbit with any external router I have through long (about 2 meters) and short (0.1 meters) cables. Both of them also works at 1Gbit with evaluation board ZCU102, which have DP83867IR in 64-pin package.
Custom board with DP83867IR can have stable connection with KSZ9896-board only at 100Mbit. At 1Gbit I can't have a stable connection between boards.
This is signal from one of ethernet pins: after some negotiation link established, but less than in a second it disappeared and negotiation started again.
