fcs error scrndump.docx (156 KB)
What is this? My log shows “fcs error” on link attached to an interface… what the hell does it mean and where is it coming from?
Verify speed and duplex at both ends of this interface.
It mean that the crc on the layer 2 is incorrect.
I have seen this before with mismatch duplex or faulty cable.
well, checked that. Both ends are the same setting. So I don’t know. Didn’t happen anymore today. Lets see what happens tonight…
I am having the same issue.
FCS Error Ether 8
Replaced cable (tested and verified) power supply (also tested) and checked for duplex (100mbs router and radio) Still getting error.
Several Radios are connected to the UBNT sector. Would I need to check them as well?
Any other ideas?
I believe this is part of the flow contol mechanism that was added to Ethernet interfaces in RouterOS 6.12+
Not a new concept in Ethernet but new to MT.
I had this issue on one of my CCR1036 interfaces connected to a SAF backhaul. The SAF turns flow control on (no option to turn it off) and I had not turned it on in the CCR1036. Turned it on and now its happy.
I’ve discovered that many backhauls implement flow control on the Ethernet port, wheather they state it in the manual or not.
Interface Warning : eth1 Connection fcs error on link???
please help to solve this problem
FCS arror indicates a physical problem either with the cable or the connected devices ethernet ports.
well, might be but the MT software is either too sensitive or has bug. We use latest stable softwares and firmwares and have at several places fcs errors coming up at times. Sometimes for months nothing and than suddenly one, some or many ports on a router show fcs errors. Sometimes only 2,3 a day, sometimes several per minute and then suddenly stop to not to come back for weeks…
This is a router in a cool stable basement were nothing happens…
I’m having this same problem on ccr 1036 2sfp + and the problem appears on all ports is varying by day which port will display error and sometimes in a matter of minutes presenting this error the harder was that it started presenting only in ether7 and with the passing of the time present in ether1,2,3,4 is random
The solution to the problem of FCS error, is because the wiring is damaged, is not adequate, etc. it happened to me the same in Rb2011 uiasrm on the switch 1 gigabit ethernet had a 10/100/1000 modem connected and both were connected with a rj45 cat 5e cable and showed me that error frequently until I changed cable and solved issue
I also have this message in my log during 6 days
The connected machine is a Raspberry 3b+, I disconnected during 6 days and the message was logged. Now I am back, reconnected the RPI and no message.
The cable is long: 10 meters !
Antenna effect ?
I’d rather vote for a small dust particle in the connector unless you operate your setup in an environment with a high electromagnetic interference - on a power plant or substation, or next to an AM broadcasting station.
We’ve been experiencing the same fcs error every once in a while.
Tried power cycle reset, it works fine for a while but after a few hours or day errors come back again.
My wireless network suffers as it loss it connectivity or work intermittently.
What would be the possible cause of it?
Possible solutions?
Thanks in advance guys
@Kikomachine, on wireless or wired interface?