RB2011UAS (v.6.4 - rb3.08) & CRC ERROR

RouterOS General
1

Hello to All!

I’ve a new RB2011UAS…with firmware v.6.4 and routerboard firmware 3.08
I’ve connected all 5 Giga Ports to one Cisco Giga Swtich with 2mt cable cat6.
The Ether3 RX bad CRC (Rx FCS Error) and go down/up.
No problem on over other MKT Giga ETH (1, 2, 4 and 5)
I’ve moved the cable to Ether6 and the problem over that ethernet has disappeared.

Is it a “software” or “hardware” problem?

Thanks and best regards

Sim

2

Hello!

After 6h without problem (over eth6) i’ve moved newly the cable to ether3… same problem!

Could you tell me if it’s an HW or SW problem?

Thanks



2 R name=“ether3” driver-rx-byte=358 383 988 driver-rx-packet=632 837
driver-tx-byte=1 025 577 212 driver-tx-packet=881 271
rx-bytes=360 804 713 rx-too-short=0 rx-64=271 840 rx-65-127=13 324
rx-128-255=4 637 rx-256-511=54 083 rx-512-1023=87 968
rx-1024-1518=201 138 rx-1519-max=12 rx-too-long=0 rx-broadcast=84
rx-pause=0 rx-multicast=3 927 rx-fcs-error=376 rx-align-error=0
rx-fragment=0 rx-overflow=0 tx-bytes=1 027 000 409 tx-64=117 347
tx-65-127=23 204 tx-128-255=5 891 tx-256-511=49 617 tx-512-1023=46 694
tx-1024-1518=638 228 tx-1519-max=0 tx-too-long=0 tx-broadcast=151
tx-pause=0 tx-multicast=125 tx-underrun=0 tx-collision=0
tx-excessive-collision=0 tx-multiple-collision=0 tx-single-collision=0
tx-excessive-deferred=0 tx-deferred=0 tx-late-collision=0

3

I don’t know if this is the same issue I’ve run into, but I have regularly had CRC errors when connecting anything running RouterOS to any Cisco equipment.

After playing with the duplexing I managed to get reliable speeds out of it, most of the time.

I have no problems with any other devices, only Cisco. Some of the newer Cisco equipment doesn’t seem to have the same issue. Might be worth updating your Cisco if possible.

4

Hello Oldman,
thanks for your reply.

My Cisco is WS-C2960S-24TS-S with firmware 12.2(58)SE2 (C2960S-UNIVERSALK9-M).
It’s the last stable version for 12.2 series…
And why i’ve the problem only with that MKT-eth3 port?
All other MKT-Giga ports are connectet to that Cisco

Thanks!

5

It sounds more like a hardware issue.
If not that, then probably an RMA (warranty) is the only easy way unless you know how to check the trace connections and about soldering on the PCB.

6

Hello sergejs,
thanks for your reply.
We have opened RMA/warranty for that product!
No problem with other 6.4 products
Best regards

7

Hello,

unfortunately we noticed the following situation:
We got a new product (Mikrotik RouterBoard 2011UAS-RM), which is under warranty, and that came to us already defective.
We already have a valid RMA for returning it under warranty, but the procedure enacted by your partner doesn’t seem to allow a replacement, but instead we have to wait a long time between:

  • Sending it by courier to the partner.
  • Forwarding from your partner to Mikrotik.
  • Do an analysis of the damage
  • Repair (if possible), and sending it back to your partner.
  • And finally, sending it back from your partner to our company.

Nowadays it’s now a feasible option to wait all this time for a product that came already defective, that has only six days of life, and we are expecting a replacement instead of going through this whole process of evaluation and repair.

Is this your way of dealing with analogous situations or its simply the modus operandi of the partner?

Best regards

8

I am also having some really odd problems. I installed my Mikrotik RB2011UAS-RM and non of the IP filters that use the chain “forward” work at all, nothing even shows up with logging all forwarded traffic, HOWEVER!!! traffic does pass to all servers behind the mikrotik. So traffic is getting to the severs, but the mikrotik doesn’t see any of that traffic. I emailed Mikrotik support, attached the supout.rif file and they still haven’t figured it out. At what point do I deem this mikrotik defective?
Also when I plug anything into ether8 it becomes unreachable, only when in that port??? does any of this make sense?

9

I have seen this in 2011 and 6.x of ros. Its something really wired happening in some of this devices. Also with “no link to Ethernet” etc. Run the 5.x to 2011, and its “no” problem. PS, in the new, 2011 (not rack) with LCD, that come with 6.x pre installed, you need to netinstall 5.x. Just downgrading, will make the router “crazy”.

10

CRC Errors are most frequently due to duplex mismatch.

Speed and Duplex can be set only one of two ways to work properly for 100 Mbps links

  1. Auto speed/duplex set on each side of the link
  2. Hard coded speed and duplex set on each side of the link

If you hard code one side and leave the other side at auto, you will get a duplex mismatch and CRC errors. 1 Gig is a little more forgiving since most vendors don’t implement half duplex for gig.