hello dear friends

I write for the first time on the forum. We have a small network with 100 users, which in most users use mikrotik routers. We have a Airfiber link + Mikrotik CCR1036-12G-4S at the end as primary router. The capacity of Internet lines before MT is 250 Mbit / 120Mbit (tested with computer!)
In the case when I tested by the bandwidth test with MikroTik result is the same-speed (250 Mbit / 120Mbit)
Running a short test like speedtest.net just shows a slow download (max 25-35Mbit) every test.
Upload is NORMAL.
Router is loaded constant 30-90 Mbit down / 25-50 Mbit up, where set many rules of NAT, firewall, and two bridge.
Overnight is extremely decreased permeability of the router in the direction of the download
CPU load is always max 1%, RAM 560MB
Also, none of the 36 processors has reached more than 1%

Please help me

some users have reported wired ethernet negotiation problem between CCR and Airfiber, check ethernet for errors

sometimes is needed to tweak the auto negotiation for a manual setting on one or both sides (CCR and Airfiber)

AirFiber which, AF24, AF5, AF5x? I've never had to hard set the speeds on an AF to CCR ethernet link. Sometimes you have to fix the tower grounding and make a new cable that will actually negotiate at 1000Mbps/Full-duplex. Every negotiation issue we've had was curable by getting the ethernet and ground loop issues corrected.

This covers some of the grounding issues:

http://forum.netonix.com/viewtopic.php?f=30&t=188

This mentions some of the cable making issues:

https://community.ubnt.com/t5/airMAX-AC ... -p/1032341

I've not seen this covered on the MikroTik forum, so sorry for posting off-site links. Doesn't mean they weren't covered here. Just that I haven't seen them.

AirFiber which, AF24, AF5, AF5x? I've never had to hard set the speeds on an AF to CCR ethernet link. Sometimes you have to fix the tower grounding and make a new cable that will actually negotiate at 1000Mbps/Full-duplex. Every negotiation issue we've had was curable by getting the ethernet and ground loop issues corrected.

This covers some of the grounding issues:

http://forum.netonix.com/viewtopic.php?f=30&t=188

This mentions some of the cable making issues:

https://community.ubnt.com/t5/airMAX-AC ... -p/1032341

I've not seen this covered on the MikroTik forum, so sorry for posting off-site links. Doesn't mean they weren't covered here. Just that I haven't seen them.

i think the reported issues was on airfiber 24

interesting articles about grounding and cabling thx for sharing

OK
We have AF 5G (first we have 24G but we removed due known problem with rain etc)
Once I remove the "auto negotiation" on MT but the entire link break down.
Airfiber has no manual option 1 Gps!! Just 100Mbit half and full....
AF is not connected directly to MT but it comes at MT over GIGABIT switch

I forgot: between AF and MT is GIGABIT switch, which also serves and help diagnostic link.

After the mail sent yesterday to the Mikrotik support (with supout. rif file) today everything magically works without any additional settings
You save me hours and hours thinking what could be wrong

however big thank you