I have a 433UAH with version routeros 3.3

My setup:
desktop (with winbox) <--(utp)--> (ether1) 433UAH (ether3) <--(utp)--> laptop
[*]both utp are plain kabels (no crossing).
[*]The laptop had address 192.168.253.252 netmask 255.255.255.0

The only config line added is: The laptop now is able to ping the 433UAH and the otherway around is also working.

Now i upgrade routeros to 4.3. The setup remains the same and, and the same configuration is used.
Now the laptop cannot ping the 433UAH and the 433UAH isn't able to ping the laptop.
Wireshark on the laptop doesn't show any incoming packets from the 433UAH and a 'torch' on the 433UAH isn't showing any traffic received from the laptop.

The 433UAH has a ICPlus175D switch chip, so there is the new switch functionality after the upgrade. But i would expect that no extra configuration is needed to make above example to work. What am i doing wrong? And is there a way to get it working?

there is no v4.4, you probably mean v4.3

there is no v4.4, you probably mean v4.3

I was going to say, "Where's my notification"

there is no v4.4, you probably mean v4.3

Sorry.. you're correct...., v4.3

found the edit button.. so changed it into 4.3

I have a 433UAH in I get exactly the same problem: after the upgrade, eth2 and eth3 are dead.

It works fine with 4.2.

I have the same trouble
eth2 - connection lost
RB433UAH 4.3

4.2 work fine

how to troubleshoot ?

wait for the v4.4 - it will fix that