I a using the very latest .12 code but this problem has been happening for several versions before this. The unit is a rb230.
I have a Cisco 2950xl switch.
Setting the rb230 to anything other than 10mb half duplex the cisco shows the port resetting all the time.
100 full duplex it resets 10 times an hour. 100 half duplex it resets about 4 times every hour.
10 half duplex it dosnt’ reset at all.
I have turned the auto detect feature both in the cisco switch and rb230.
Any ideas?
-Michael
I am experiancing the same thing with a RB532. Mine will NOT link up if all is set to auto. I have mine set to 10/full and am sending one ping every 10 seconds with netwatch and I will loose connection for 5-10 seconds every hour. Almost to the exact hour.
I was also seeing this with one of my RB532s. To get a stable link on ours we set the other device to 10 full and the link came up stable at 10 full when it was set to auto. If I set the other device to 100 full then the link just bounces over and over again.
If you’re talking about 100mbit ethernet connection just put a cheap 5 port switch to act as a repeater between the two machines. Should work. Or make the cable between the two longer.
How much longer? I’m using a standard 1.8m cable between an RB and a cable modem, tried a 5m cable, still the same.
are these 100% manufactured cables complete with connectors or did you attach the connectors yourself? (just curious)
Did them myself. They work well on other equipment I have used them on.
I got on a cisco mirc group and worked with my switch a little bit. Basicly we set both sides to auto and it came up 100/mb and full duplex.
Monitored it for an hour and all was good.
Today I go back and check and the cisco status look good at:
FastEthernet0/21 is up, line protocol is up
Hardware is Fast Ethernet, address is 000b.46f0.aa55 (bia 000b.46f0.aa55)
MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:08, output 00:00:01, output hang never
Last clearing of “show interface” counters 19:42:01
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue :0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
524165 packets input, 98576638 bytes, 0 no buffer
Received 2840 broadcasts, 0 runts, 0 giants, 0 throttles
1 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 1182 multicast, 0 pause input
0 input packets with dribble condition detected
758201 packets output, 528975709 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
but the log shows
3w6d: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed
state to down
3w6d: %LINK-3-UPDOWN: Interface FastEthernet0/21, changed state to up
3w6d: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/21, changed
state to up
about 50 times over the night :evil:
auto is usually gold. of course fixed is what you can do after you found what works. ever considered trying one of them cables that the connectors are attached at the factory? just for reference i mean.
cisco switches do have a reputation for being troublesome with non-cisco equipment. had a few cases i had to give up on in which afterwards it turns out i didn’t know the difference between the different cable standards. 
2m is the IEEE minimum. I think with the current 2.9 (2.9.10+) you can control the MDI-X on/off for the Eth1 (first Ethernet port). For Eth2,3 we would have to put jumpers on the board and have decided against that.
John
I have tried manually setting both sides to 10/mb and half duplex up to 100/full duplex and all combinations in between.
When I set half duplex I get a lot less drops but get a lot of collitions.
When I set everything to auto i get 100mb full duplex no collitions but lots of drops.
I just replaced the patch cable between the switch the poe injector from a short 1m patch to a 3m patch cable.
The injector has been replaced, and the unit is on the roof with a 2 story run with outdoor ethernet cabling.
The mikrotik unit does not show any logs of the unit restarting or any problems with the ethernet port.
-Michael
How’s that done? Can’t seem to find it anywhere in Winbox or Terminal.
Check
interface ethernet
interface ethernet> set 0
changes properties of one or several items.
<numbers> -- item numbers
name -- Interface name
mtu -- Maximum Transmit Unit
mac-address -- MAC address
arp -- Address Resolution Protocol
disable-running-check -- Disable running check
auto-negotiation -- When enabled the interface "advertises" the maximum capabilities to achieve the best connection possi
ble
full-duplex -- Defines whether the transmissionof data appearsin two directions simultaneously
cable-settings -- Ethernet cable type
long-cable -- Changes the cable length setting
speed -- sets the data transmission speed of the interface
comment -- short description of the item
disabled --
where?[/code]
We have made it a while ago, but it wasn’t included in configuration.
In v2.9.14 there will be such argument:
mdix-enable=yes
What does mdix do?
I am still getting the port reset five times an hour. This knocks gamers off there servers and cuts our voip calls off.
I have tried using another switch, locking the port speeds, etc etc. now its all set back to auto. Now changes. No logging erros on switch or mikrotik unit.
-Michael
My issue was that the RB was connecting/disconnecting every second when plugged directly into a 10Mbit cable modem router. I solved this by sticking in an RB230 unit in between.
You can solve this in much cheaper way 
Put the cheapest switch you can find between Routerboad and your cable modem.
I solved my Motorola Canopy problem on this way, as it also have problems with autodetecting crossover/straight cable connections, as well as 10/100Mbit negotiation
Will the cheap router solution work between two mikrotik routers as well?