Hi everybody!

Today I had enough free time as I thought to update the RouterOS on my 2 Mikrotik routers from ver.6.45.1 to ver.6.45.2. So I did it as usal. Just copied new OS files from the appropriate section on Mikrotik official website (https://mikrotik.com/download) devoted to RB4011 to the router file destination (Files\File list) and rebooted. What a great surprise I had finding out after reboot and upgrade that I had lost access to Internet. After carefull review I found out that my router lost it's ability to obtain the ip-address from ISP via DHCP. As my ISP provides dynamic ip-addresses only by DHCP that was really a quest. What made the situation worse was that I had not only upgraded the RouterOS but the firmware too. Now I know it's a bad habbit to upgrade both of them. Will never do such reckless things again. The good point was I always make backups in .backup and .rsc. So all configurations were safe. Buttt!!! It was a real brainstorm how to downgrade the firmware. As to the RouterOS - there was no problem and the process is clearly described in many sources. But I did a long investigation on third-party forums how to downgrade the firmware. Now I want to address to the Mikrotik support team. Why is there no information on Mikrotik official website? Please do your job. If anyone encounters such a problem - the issue is as follows:
1. Downgrade the RouterOS to the needed version (you can find the version you need here: https://mikrotik.com/download/archive).
2. In New terminal window type: system routerboard upgrade (Yes,yes. This is not a mistake. You have to type not DOWNGRADE but UPGRADE!!! Though in fact your firmware will be downgraded to the current RouterOS version that you have downgraded to in the 1 step.
3. After a promt DO YOU REALLY WANT TO UPGRADE THE FIRMWARE Y/N just type Y and the firmware will downgrade!
4. Reboot the router.
5. Done.
But my bad luck at this time was not gone. After downgrading both firmware and RouterOS to the previous version my router still refused to obtain the ip-address from the ISP via DHCP. I got in touch with the ISP support and they checked that the switch port my RB is connected to is set properly (negotiation off, speed-duplex force1g-full nonegotiate slave) as only such settings work in RB4011 SFP+ cage when using SFP 1G modules. After the ISP confirmed that the settings meet my requirements I unplugged the RB4011 (pay attention, not rebooted but unplugged. As it turned out that on reboot the SFP module stays powered on) and in a minute plugged in again. The RB4011 booted and at this time obtained the ip-address via DHCP correctly without any issues.
I don't know what the Mikrotik engineers did wrong but I do strongly advise you not to update to RoterOS version 6.45.2 and keep away from it. They call it stable but my experience shows it's faulty. Hope all Mikrotik users are the same level skilled as me otherwise there are not so many ISPs who can or will offer as skilled support. My e-mail is SL4529@GMAIL.COM if you have similar issues or any questions left.

But my bad luck at this time was not gone. After downgrading both firmware and RouterOS to the previous version my router still refused to obtain the ip-address from the ISP via DHCP. I got in touch with the ISP support and they checked that the switch port my RB is connected to is set properly (negotiation off, speed-duplex force1g-full nonegotiate slave) as only such settings work in RB4011 SFP+ cage when using SFP 1G modules. After the ISP confirmed that the settings meet my requirements I unplugged the RB4011 (pay attention, not rebooted but unplugged. As it turned out that on reboot the SFP module stays powered on) and in a minute plugged in again. The RB4011 booted and at this time obtained the ip-address via DHCP correctly without any issues.

thank you for posting your observations .... especially the part where you UNPLUGGED then after a minute plugged in again and this time your SFP+ INTERFACE obtained the ip. very interesting indeed.

Can you please tell us which SFP MODULE you are using? Is it the one provided by your ISP or one that you purchased?

The SFP module I'm using is a local brand (SNR) used by my ISP. So I had not so much of a choice unless use the one advised by my ISP. All I can say it's parameters on my side are TX 1550 RX 1310.

But my bad luck at this time was not gone. After downgrading both firmware and RouterOS to the previous version my router still refused to obtain the ip-address from the ISP via DHCP.

Hi, at 6.45.1 there is such a problem, if the switch of the ISP is turned off and turned on after a short period, due to the loss of light, let's say. You have to pull the sfp module manually.

Put 6.46beta16 - there is no such problem.

PS
6.45.2 complete shit for RB4011

Maybe you might wanna try 6.45.3
I saw it on the main download page but have not updated need to download manually I think.


But for me 6.44.3 is my most stable at the moment.

6.45.3

*) rb4011 - fixed SFP+ interface linking (introduced in v6.45.2);

6.45.3

*) rb4011 - fixed SFP+ interface linking (introduced in v6.45.2);

Very strange that no official announcement on the Forum and when using Winbox "Check for updates" only 6.45.2 displays.

I prefer to stay on 6.45.1 until Mikrotik team stops this storm of bugs and lets the community know we can safely update avoiding significant issues. Otherwise will have to think twice if it's worth using Mikrotik hardware once you may quite unexpectedly get a swarm of bugs and issues.

I prefer to stay on 6.45.1 until Mikrotik team stops this storm of bugs and lets the community know we can safely update avoiding significant issues. Otherwise will have to think twice if it's worth using Mikrotik hardware once you may quite unexpectedly get a swarm of bugs and issues.

They do warn you to stick with "longterm" for mission critical installations.

https://wiki.mikrotik.com/wiki/Manual:U ... ase_chains

Each user has to decide for him or herself what they value most. If you value stability and lack of bugs, then "longterm" is probably your best bet.

I like the fact that I get a choice of which release chain to use. There are other vendors where you don't get a choice.

I had the same issue with SFP completely stopped working, there was no traffic, nothing helped so I updated to beta FW.
But the problem repeated on 6.46beta38, so I downgraded to 6.45.5 and it’s up again.
It is definetely a problem with RouterOS and I can replicate it.

I have downgraded to RouterOS 6.44.5 and can state the stable functionality of the RB4011. Now I'm a bit puzzled when and whether it's a good idea to upgrade to any later release. The point is that all releases beginning with 6.45.* have different issues causing malfunctions of either SFP+ interface or WiFi interfaces.
It's a pitty that MikroTik keeps silence as though the problem doesn't exist.

6.45.3

*) rb4011 - fixed SFP+ interface linking (introduced in v6.45.2);

Fixed? I do not believe its fixed based on the experience in the Following thread"
MikroTik RB4011 SFP+ GPON

How disappointing and unprofessional!

We simulate in our lab this behavior too,

The issue is when the router is rebooted or shutdown with the SFP transceiver plugged in into the router, is not detecting the link after power-up, doesn't matter if the auto-negotiation is enabled or not, the behavior is the same, also if you disable and enable again the SFP+ interface the link keeps down and only when you unplug and re-plug the SFP transceiver the link is established. this happens with several SFP transceivers (not only with GPON ONU SFPs).

We tested with many RouterOS versions in both branches (Stable and LongTerm) without any luck, we reported this issue to the Mikrotik Support team and they are investigating this issue. we are providing all the stuff that they need to keep forward with his research.

Hello,

Thank you for these details. We would like to ask you, maybe you could somehow copy and send the contents of the EEPROM of this module to us? Perhaps this information could help us.
Also, we want to ask you, if you have the opportunity, please could you check how this connection will works for you with this module with RouterOS version 6.45.8.
Below we attach a link for this version:
https://download.mikrotik.com/routeros/ ... 6.45.8.npk

Best regards,
Vjaceslavs

Also we reported an Issue/FeatureRequest related with the SFP information is not displayed on Winbox viewtopic.php?f=3&t=165386&p=812901