hEX: Why my interface switch from 1Gbps to 100Mps?

RouterOS General
1

Hi,

I have one interface connected to my ISP fiber hardware via ethernet cable. both my router hEX and the fiber hardware supports 1Gbps, and on winbox shows that:

But for some reason, it’s change to 100Mpbs, without any manual settings.. I just know when my internet start slowing down.. and I’ll look at the interface and it’s Rate as 100Mbps…

Any idea for that?

Thanks!

2

The screenshot is totally useless.

Change ethernet cable and clean the contacts (with appropriate product).

3

I already did that.. Changed the cable and clean everything.. maybe something logical?

4

Logical: auto negotiation may fail to allocated 1000Mbps at certain times.

Loose wiring, oxydised contacts? 1000Mbps needs all wires to be OK, 100Mbps needs only 4.

https://hardwaresecrets.com/how-gigabit-ethernet-works/

“Ethernet Cat 5/6 cables have eight wires (four pairs), but under 10BaseT and 100BaseT standards (10 Mbps and 100 Mbps, respectively) only four (two pairs) of these wires are actually used. One pair is used for transmitting data and the other pair is used for receiving data.”
“Also, instead of using just four wires of the cable, Gigabit Ethernet uses all wires. On top of this, all pairs are used in a bi-directional fashion”