RB751G-2HnD switch ports down and up

Hardware MikroTik hardware general
1

Hi, just bought RB751G-2HnD to is as home router
Firmware 3.0, upgraded to RoutersOS 5.22

Setup WAN port 1 - dhcp, pptp
LAN - port 3 - home computer
LAN - port 5 - smart TV

Router contiouniusly switch me off and on.
Logs show:

86 Jan/23/2013 20:11:07 memory interface, info ether3-slave-local link down
87 Jan/23/2013 20:11:08 memory interface, info ether2-master-local link down
88 Jan/23/2013 20:11:10 memory interface, info ether3-slave-local link up (speed 1000M, full duplex)
89 Jan/23/2013 20:11:11 memory interface, info ether2-master-local link up (speed 10M, half duplex)

90 Jan/23/2013 21:06:57 memory interface, info ether3-slave-local link down
91 Jan/23/2013 21:06:58 memory interface, info ether2-master-local link down
92 Jan/23/2013 21:07:00 memory interface, info ether3-slave-local link up (speed 1000M, full duplex)
93 Jan/23/2013 21:07:01 memory interface, info ether2-master-local link up (speed 10M, half duplex)

94 Jan/23/2013 22:04:58 memory interface, info ether3-slave-local link down
95 Jan/23/2013 22:04:59 memory interface, info ether2-master-local link down
96 Jan/23/2013 22:05:01 memory interface, info ether3-slave-local link up (speed 1000M, full duplex)
97 Jan/23/2013 22:05:02 memory interface, info ether2-master-local link up (speed 10M, half duplex)

any tips what going on?

2

Hi,

Try turning auto-negotiate off and then set the link speeds manually, if the manual link speeds you have set still fail then try a different speed + duplex.

I have seen this a few times with other vendors…

Hope this helps

3

thanks for suggestion

computer link was 1G

First i logged into winbox, into interfaces and uncheked Auto Negotiation checkbox in ether3-slave-local properties, speed radio was at 100 Mbps
Then clicked buttun Apply and immediately lost connection to router. Lost dhcp ip, Winbox don’t see it, and even with manually assigned ip to computer, no ping.

Then i switched computer cable from router port 3 to port 2 and connection restored on ether2-master-local again 1G, all working.

After that i switched speed at computer side to 100 Mbps full duplex, all working good.

Very strange behevoir.

Will se how it will work at 100 Mbps

Support responded with suggestion to check cable. Will try this tomorrow with simple cable tester.

4

No up/down since i set speed to 100 mbps on computer side. working stable.

5

Is the NIC on your computer a 1Gbps NIC or a 100Mbps NIC?