Hi!
I have the "unusual" task to reduce the network speed from 1Gbps to 100 Mbps.
The reason is I have Ethernet device at the end, which can work only on 10 and 100 Mbps.
What device I have to choose? For example, mAP 2nd is a good choice? Apparently very simple 2 ethernet ports router is necessary.
Further, shall I just select 100 Mbps speed on the second LAN, and can I use the same IP address on both LAN?

If the device can work only on 10 or 100 it will autonegotiate at 10 or 100.
If for some reason autonegotiation doesn't work you can set the speed manually.

How exactly I am supposed to set the speed manually?

Thanks, it is clear, what about the device - mAP 2nd is OK? Can I assign the same IP address on ehter1 and ether2, to avoid NAT, or there is some other trick?

Thanks, it is clear, what about the device - mAP 2nd is OK? Can I assign the same IP address on ehter1 and ether2, to avoid NAT, or there is some other trick?

You don't need router for the task, any managed switch can do that.
Or I think any unmanaged 100mbit one will do the trick too.

And even if you still want to use mAP - you should bridge both ports together and that's it.
No IP needed on that bridge at all (of course if you are not going to access the mAP itself via one of ethernet ports, then you can assign IP to the bridge).

Understood, thank you very much, xvo!