Im having issues with ntp client.
2 rb433 and 2rb951 doesnt sync the clock time with ntp servers.
anyone else having this problem?
elmer, I’ve got very same problem with my RB/750 upgrading it to v6.10.
How do your hardware “work” exactly?
My RB/750 turns all LEDs ON (despite of real state of Ethernet ports) and no reaction in WinBox, no traffic at all (after normal reboot) – I’ve sniffed any packets with WireShark software.
If I reset device to defaults (short circuit contact hole with screwdriver or 1-2 sec RESET while powering on) hardware lights Ethernet LEDs right according to real port connections – but no any Ethernet packets too.
Finally I’ve tried to netinstall some versions 5.xx and 6.xx in hope to reanimate the device. Pressing RESET button untill ACT LED goes off gives device to network (IP, bootp, visible to netinstall) and makes netinstall process possible… but loading any firmware doesn’t repair my RB/750 after rebooting 
[Ticket#2014031166000717] support says:
unfortunately no, this model does not support it [RS-232]. It may have serial port pads on
pcd, but they won’t work without special software on router which we do not share
with public.
…
whole picture looks awflly like problem with nand flash on router, it could have
died of old age so to speek or just hardware failure of this specific chip. In
this case router hardware replacement will be required.
It’s strange that two RB751U-2HnD devices have been upgraded to 6.10 successfully and work OK for now.
Please get us to know about progress with yours (and details, please).
P.S. My RB/750 worked not hard in good datacenter conditions for ~ 2 years. Sad
Try this:
whit reset BUTTON pressed, (not the hole pin with screwdriver) plug the power, after 2 sec stop press the button.
Wait,
if the rb start, open winbox and update BIOS:
put BOTH this file in “files” folder
http://i.mt.lv/routerboard/files/ar7240_3.13.fwf
http://i.mt.lv/routerboard/files/ar7100_3.10.fwf
and launch
/system routerboard updateDO NOT REBOOT
After that prepare netistall 6.10 with 6.10 software
http://download2.mikrotik.com/routeros/6.10/netinstall-6.10.zip
http://download2.mikrotik.com/routeros/6.10/routeros-mipsbe-6.10.npk
and launch this on console:
/system routerboard settings
set baud-rate=115200
set boot-delay=2s
set boot-device=try-ethernet-once-then-nand
set boot-protocol=bootp
set cpu-mode=regular
set enable-jumper-reset=yes
set enter-setup-on=delete-key
set force-backup-booter=no
set silent-boot=nonow reboot and use netinstall without keeping old configuration
I’m glad to do it, but:
My RB/750 > turns all LEDs ON (despite of real state of Ethernet ports) and > no reaction in WinBox> , no traffic at all (after normal reboot) – I’ve sniffed any packets with WireShark software.
If I reset device to defaults > (short circuit contact hole with screwdriver > or 1-2 sec RESET while powering on> ) hardware lights Ethernet LEDs right according to real port connections – > but no any Ethernet packets too> .
Simply I can not see device with WinBox (MAC or IP) at all. Only Netinstall sees it somehow.
Forget the hole with the screwdriver.
- before power the rb, press reset button and leave pressed, insert power plug, and wait until devices are visible in netinstall (15~20sec) [assuming the pc is working], now release reset button.
- If you can see correctly the device on netinstall 6.10, try to install the package 6.10.
- If netinstall fail, repeat the steps 1-2 with netisntall 5.26 AND RouterOS 5.26.
- When devices show “waiting reboot” on netisntall, fast remove the power,
- before power the rb, press reset button and still with reset button pressed, insert power plug, and when any led display up, release reset button [load backup bios].
- Wait if rb start and follow the previous instruction to upgrade the bios.
Delete this post. I found my problem.
I have just netinstalled 6.10 on RB2011UAS-2HnD and upgraded FW from 3.10 to 3.12. I was not able to run config script downloaded from v.6.9. so I did it by copy-paste thru terminal.
Reason: The Netwatch is missing in Tools.
How to get Netwatch back? I need it.
I am a dumb. Advanced tools package is missing… sorry everyone for disturbing.
rextended, made all your checklist exactly (thanks for trick #4) twice with netinstall6.10+routeros6.10 & netinstall5.26+routeros5.26, but thats’ doesn’t help to repair my device.
After all, I can not see its MAC with WinBox in default boot mode (RESET button shortly pressed while power on) and free reboot.
Made one last try with [use SAME version of Netinstall and RouterOS!]
http://download.mikrotikindonesia.com/index.php?dir=Firmware/V5/routeros-5.11/&file=netinstall-5.11.zip
http://download.mikrotikindonesia.com/index.php?dir=Firmware/V5/routeros-5.11/&file=routeros-mipsbe-5.11.npk
Yes, that version!..
I have the same problem, when I forget to upgrade BIOS [firmware] before upgrading some SXT to version 5.26 or 6.x
But after I successfully boot RB with old software [or backup BIOS] I can fix with the method described before.
If you reach to reboot properly the board, first do bios upgrade as I explain on previous post.
Hi, I have a problem using option DHCPv6-PD to send ipv6 prefixes via pppoe, the option send the prefix and create the route, works well and hangs dhcp when pppoe conection drop.
If I disconect normaly them dhcpv6 release the prefix but when hangs suddenly it simply stay conected and dhcpv4 stop too, cant get new prefixes or release the one with pppoe. When that happens one core of my cpu goes 100% and only a reboot normalize it.
Yes, I have the same problem long time. Mostly on the bridge interface or on the VRRP interface. After rebooting the IPv6 do not works on the interface.
bridge - The bridge do not have a link local address after reboot sometimes. There is in the /ipv6 address listed correct link local address but interface is (unknown). After disable/enable bridge then is created new record with correct link local address and correct interface and IPv6 works. All bridges have admin MAC set.
VRRP - After rebooting the vrrp interface which starts as master sometimes do not operate with IPv6 (link local address is correctly assigned). After disable/enable or switch slave/master state IPv6 starts working.
These problems begin with ROS6.3 and ROS5.25 on RB1100AH/AHx2. Reported long time ago, never answered.
The bridge problem after resolving with disable/enable looks like this:
/ipv6 address print where address="fe80::ff:fe00:12/64"
Flags: X - disabled, I - invalid, D - dynamic, G - global, L - link-local
# ADDRESS FROM-POOL INTERFACE ADVERTISE
20 DL fe80::ff:fe00:12/64 (unknown) no
21 DL fe80::ff:fe00:12/64 bridge-wan no
Done.
But after reboot (fast power off when “Waiting…”, then power on with RESET button pressed till LEDs on, then power off/on reboot) I see no my device RB/750 in WinBox
So I can’t do next part of firmware/bios upgrade procedure. All LEDs on, no any network activity/visibility
I’m very glad if your receipt helps you or somebody else in same trouble… but not me, sorry.
For now I’ve got LEDs box for Christmas Tree and spare 12V Power Supply 
Thanks @Majklik, opened a ticket again 
Hello Folks!
Upgraded rb2011 and rb750 to RoS6.10 from RoS6.7, all l2tp links fails more or less, nothing in logs they simply stop working after some megabytes of data traversing them, average is 2-3 Mbyte, then dead.
This is VERY serious problem for our business, economic loss is result this time, many co-workers just sit doing nothing!!!
The same goes for routing marks, they are also ignored after upgrade.
Now trying to rollback.
Yes, I agree. I see this from ROS6.7 days (at least on the RB800). A profile show that a dhcp task consumes my CPU.
v6.10 every hour disconnect openvpn.
probably, it’s already fixed in pre-release:
What’s new in 6.11 (2014-Mar-18 11:14):
*) ovpn - fixed TLS renegotiation;
Actually are another bug, also present on 6.8, 6.9 and 6.10
and go worst on 6.11:
Winbox connection from pc directly connected on the gateway/pppoe server [really not matter where pc are connected]
to one CPE on IP obtained from pppoe with MRRU set,
is continually broken after receiving some data from CPE.
The problem regard exclusively Winbox service on RouterOS, bandwidth and other parameters working perfectly with very low latency.
On 6.7 is perfectly stable.
The problem is not present if one ip for wlan1 are used.
I believe this issue is somehow v6.10 related .. I did not experience this kind of problems with older versions of routeros.
http://forum.mikrotik.com/t/rb2011uas-2hnd-stops-responding-spontaneously/75301/1
JF.