I just bought a RB750Gr3 to upgrade my old Linksys. Since I was warned of ROS's complexity, I assumed there would be a steep learning curve in getting this to work. So when I face problems right at startup with simple issues, I did not worry about it. My config is as follows:

1. Original firmware: 6.47.9
2. Upgraded firmware: 6.49.2
3. Current setup: Ether1 setup as PPPoE to my service provider (ROS's pppoe default setup)
4. Remaining ethers bridged (ROS's pppoe default setup)
5. Log file of of problem attached (the messages keep repeating as long as RB750 is kept connected).
6. Name of my local service provider is "ACT FIBERNET"

The issue:
Initially when RB750 was first setup, it refused to establish PPPoe connection for hours. Suddenly it would start and everything seemed fine till RB750 had to be restarted. Then the problem would cycle again. I have to spend hours in front of WINBOX to check when connection was going to be "UP".
Once, before the FW upgrade, when the same issue cropped up again, I changed the default setup and used ether3 as PPPoe and ether5 as lan bridge. Again after a few hours RB750 suddenly started working and connection was stable for a week.

THEN: I decided to upgrade FW to 6.49.2, hoping this would resolve all problems. After that the router is simply refusing to connect.
I think the ethernet basic connection is failing as RB750 keeps trying different speed (100mbps-fail, 1GBPS-fail etc. See log file attached).

WHY I THINK THIS IS A RB750 ISSUE:
Every other device (ancient routers, multiple laptop models) connects at first try, and remaing stable for months.

PLEASE HELP AS I DONT WANT TO RETURN MY RB750.

Ramesh

Do not despair you are not the first or last to go from a dumb device that works to a sophisticated device that will challenge your meagre knowledge and will require some level of understanding to configure properly. The good news is that out of the box its pretty much good to go...........
Your ISP is not straight cable so it may take a bit more work to get going.
Finally there is nothing wrong with the MT device,,,,,,,,

Giving us the log of events is a start but to provide assistance we need to see the config,,,,, your dirty laundy so to speak.
/export hide-sensitive file=anynameyouwish

Your log shows interface 3 flapping, not interface 1 (where Your ISP is connected). So, looks like You have 2 problems:

1) PPPoE connection
2) Flapping of port 3

First, problem 2:
It could be a bad cable or a compatibility thing (it happens). Try changing cable, changing port (ports 2, 3, 4 and 5 are bridged, as You said - use any of them) or changing the connected device. Do only ONE of these things at a time and test, otherwise gets quite hard to pinpoint the cause.

Now, problem 1:
Log shows You can't connect, but doesn't say why. Maybe a bad parameter, maybe just a typo of the password. At this point, follow anav's request, and post here the result of

/export hide-sensitive file=anynameyouwish

You need to do this on command line. One can get there by ssh, webfig or winbox.

ssh -> good old ssh. Just paste the command above and hit enter. Then, download the file (option "files", on the web interface) and put it here.
webfig -> All you need is a browser, the internal IP of your router, an username and a password. On the right upper corner You will find a "terminal" option. Click there, past the command and of You go.
winbox -> This one you need to download, from Mikrotik site. Connect to the router, and You will find the "New Terminal" option, on the left column. Paste command above, download the resulting file, put it here.

Thank you for the prompt response Anav and Paternot. Have attached the file as requested.

>>2) Flapping of port 3
I have been alternating between using port1 and port3. The problem remains same. Last try: port1 is wan/pppoe.
In the old firmware it did connect once using default wan port1. But subsequent problems made me change the port to 3. Now back to 1.

Also: Currently I have disconnected rb750 from wan and using only lan.

Silly goose!!

Look at your IP pool
/ip pool
add name=default-dhcp ranges=192.168.88.10-192.168.88.254

Look at your IP address
/ip address
add address=192.168.1.5/24 comment=defconf interface=bridge network=\
192.168.1.0

/ip dhcp-server network
add address=192.168.1.0/24 comment=defconf dns-server=192.168.88.1 gateway=\
192.168.1.5 netmask=24

There is nothing weird here. I don't use internet detection, but I don't think that's the cause of Your problems...

You have a flapping problem, in whichever port is connected to Your ISP - right? So, let's start from here.

1) Does Your computer connect ok with ether3? We know this port flaps with your ISP.
2) Are You connecting to a router Your ISP sent to your house? Or are You just getting an network cable from them, and hooking your Mikrotik in it?
3) Is it possible to change the network cable used by Your WAN connection?
4) What happens if You fix the WAN ethernet speed? Have You tried it, with 1Gb and 100Mb?
5) At the ethernet interface menu, what "cable test" says?

>>1) Does Your computer connect ok with ether3? We know this port flaps with your ISP.
Just tried this and Yes, it works fine. While doing this I tried every other port from 4-2 (port5 is already used by my lan). They all work fine. (What I did: Plugged my laptopn into different ports on the rb750 and got assigned an IP address from my local DHCP server. Then pinged some devices in my lan. I am assuming that is all you expected). I tried the WAN port also (port1, currently unused, but firewalled) the connection light was steady.

>>2) Are You connecting to a router Your ISP sent to your house? Or are You just getting an network cable from them, and hooking your Mikrotik in it?
No. My rb750gr3 is directly connected to the ISPs line. Network cable is my own. The ISP runs his cable till the fence. From there it is my own cable to my 2nd floor apartment patch panel. From this patch panel to rb750g3 I use a patch cable. Like I said, all other devices work fine in this setup except rb750g3.

>>3) Is it possible to change the network cable used by Your WAN connection?
I have tried different patch cables between rb750g3 and the external line (in the patch panel). No use. They all work fine with all other devices. But the main cable leading to the ISPs cannot be changed. In any case all other devices connect well and work perfectly.

>>4) What happens if You fix the WAN ethernet speed? Have You tried it, with 1Gb and 100Mb?
Tried this also. Same problem continues.

>>5) At the ethernet interface menu, what "cable test" says?
I dont remember the exact words. But it goes "link up" and then "link down" continuously.

Silly goose!!

Look at your IP pool
/ip pool
add name=default-dhcp ranges=192.168.88.10-192.168.88.254

Look at your IP address
/ip address
add address=192.168.1.5/24 comment=defconf interface=bridge network=\
192.168.1.0

/ip dhcp-server network
add address=192.168.1.0/24 comment=defconf dns-server=192.168.88.1 gateway=\
192.168.1.5 netmask=24

Sorry I missed this reply. I am not using DHCP-server on the RB750. It is assigned a fixed IP suitable for my home lan (192.168.1.5). Hope this answers your query.
In any case the wan port (ether1, using pppoe) does not even get the link established. It keeps blinking permanently.

Clearly do not understand your setup.
Please post a network diagram labelled enough to provide understanding........

Clearly do not understand your setup.
Please post a network diagram labelled enough to provide understanding........

ISP----isp-cable-----MY-FENCE(isp cable jointed with my cable)-------my-cable-----MY-PATCH-PANEL------my-patch-cable------RB750GR-WAN.PORT

I thought this setup is pretty straight forward.

Please note: Every other device connected through "my-patch-cable" works fine, when directly connected without RB750GR.

Very confusing as there is no mention of an ISP modem or ISP modem router? Will assume myfence is the ISP modem.

@anav: Don't overthink it, there's simply some router at the other end of cable. Somewhere at the "ISP" at the very left.

As for the problem, I don't know, I don't see anything obviously wrong either. Aside from DHCP server with mixed subnets, which shouldn't be there at all, if you don't use it. I'd disable detect-internet, because I've never seen it do anything useful, but it shouldn't break anything either.

Thanks, it seems we are missing something on the ISP side of things, is my reason for wondering out loud ...........

>>5) At the ethernet interface menu, what "cable test" says?
I dont remember the exact words. But it goes "link up" and then "link down" continuously.

This is the status. I was talking about one button, with "Cable Test" written on it. We know the ethernet port is flapping. We don't know why. I believe it is something with the cable. Yes, i know: other devices work with it.

Thing is: some devices are better at handling extra long cables than others. You said the cable come from somewhere, crosses your fence, has some kind of joining, passes through a patch panel, and the finally gets to your computer.

This is a LOT of cable, patches and joinings. CAT5 is certified for up to 100 meters - and this without patches and joinings. Some chipsets can use longer cables - but they are out of SPEC.

How big is the cable? How far is the joining? Is the joining just a connector, to join two cables? If so, could You remove the joining and plug the Mikrotik on the cable?

I know it doesn't solve the problem of "it works with the others" - but to solve a problem we must diagnose it first.

>>Very confusing as there is no mention of an ISP modem or ISP modem router? Will assume myfence is the ISP modem.
I dont know what device is at the ISP end. They simply provide a cat-5 ethernet cable to be attached at my end, to the RB750.
"Myfence" refers to my compound-wall where the first joint between the ISP's cable and my cable is present.

>>>How big is the cable?
1) The longest of my cable is about 150-feet appx (from the fence to my apartment's patch panel). It is a gigabit connection (though my contracted speed is 350mbps). I am mentioning this, as i read somewhere, that gigabit connection reach smaller distances. I achieved about 90-mbps on my old router.
>>>How far is the joining?
2) Joining is at the fence, 150 feet from patch panel.
>>>Is the joining just a connector, to join two cables?
3) The joint is simply the ISP's rj-45 plug connecting my rj-45 keystone jack.
>>> If so, could You remove the joining and plug the Mikrotik on the cable?
4) I am not sure this is possible as there is no power point near the fence, but will try to do this and reply. Related to this: the first thing the ISP does when I complain of connection issues is: Connect a laptop directly to their cable end (at the fence) and establish things work from their side.

>>Very confusing as there is no mention of an ISP modem or ISP modem router? Will assume myfence is the ISP modem.
I dont know what device is at the ISP end. They simply provide a cat-5 ethernet cable to be attached at my end, to the RB750.
"Myfence" refers to my compound-wall where the first joint between the ISP's cable and my cable is present.

>>>How big is the cable?
1) The longest of my cable is about 150-feet appx (from the fence to my apartment's patch panel). It is a gigabit connection (though my contracted speed is 350mbps). I am mentioning this, as i read somewhere, that gigabit connection reach smaller distances. I achieved about 90-mbps on my old router.
>>>How far is the joining?
2) Joining is at the fence, 150 feet from patch panel.
>>>Is the joining just a connector, to join two cables?
3) The joint is simply the ISP's rj-45 plug connecting my rj-45 keystone jack.
>>> If so, could You remove the joining and plug the Mikrotik on the cable?
4) I am not sure this is possible as there is no power point near the fence, but will try to do this and reply. Related to this: the first thing the ISP does when I complain of connection issues is: Connect a laptop directly to their cable end (at the fence) and establish things work from their side.

1) 150 feet is about 50 meters - already 50% of the maximum distance, by ethernet spec. You should do better than 90Mbps, if Your ISP delivers the contracted speed. Although 90Mbps is about we would see, if the router was syncing the ethernet at 100 Mbps.
3) Each connection reduces the maximum length of the cable: the original 100 meters (about 328 feet) specification admits two segments, and You already are at no less than 3, with more than 50% length - and we didn't count the cable before your fence.
4) They do this because:
a) They are responsible for their cable, and it stops at the fence. Quite convenient for them, as it removes the obligation to put fiber due to distance.
b) They want to reduce the length of the cable, as it is quite long already.

You can always use a 12V battery to power the hEX (it works from 8 to 30V, DC).
https://mikrotik.com/product/RB750Gr3

If you do this, remember to connect the fence cable to ether(2-4), and see if it works with the laptop, in Your house. This way we test both cables at the same time.

Hi Ramesh,
Greetings i know exactly what you are going through i have some of my clients who are using act broadband india
Fellow folks ACT is a metro ethernet provider and they run both pppoe and dhcp
So Mr Ramesh can u check the IP-Dhcp client most probably it will be running and even if u delete it sometimes it ll auto enable after every power cycle so don't remove it just disable it.
Ur Name has tn and are you from tamilnadu?

>>So Mr Ramesh can u check the IP-Dhcp client most probably it will be running and even if u delete it sometimes it ll auto enable after every power cycle so don't remove it just disable it.
Ur Name has tn and are you from tamilnadu?

When I select PPPoE, there is no option to disable DHCP client. Will search for it and let you know. And "yes" am from TN

No I believe he is talking about this setting which should be disabled
/ip dhcp-client
add comment=defconf interface=ether1

>>> No I believe he is talking about this setting which should be disabled
/ip dhcp-client
add comment=defconf interface=ether1

Ok, will try that 1st thing tomorrow morning.

Have spent hours trying to upgrade and then downgrade firmware. Nothing worked.

I still believe he has some low level problems with his link. From the log he posted:
Looks to me that the router can't keep the ethernet link up.

What? You sleep?
I am a bot so here 24/7

I still believe he has some problems with his ......:
Looks to me that the router can't keep the ethernet link up.

I can think of worse things .....................

I can think of worse things .....................

We all can. But let's keep optimistic, shall we? After all, if this is the end of times I want to go sleeping, just like my uncle. Not screaming in fright, like his passengers.

I tried disabling the dhcp-client, DID NOT work.

Have given up, can't spend any more time on this. Kids are screaming without net access. Wasted money on this product.

Anav, Paternot, Vinu: Appreciate all the time you given me. You guys were a great help.

Hope Mikrotik wakes up.

Hi Ramesh u can PM me i ll give my contact number will fix via phone if u want dont give up

I tried disabling the dhcp-client, DID NOT work.

Have given up, can't spend any more time on this. Kids are screaming without net access. Wasted money on this product.

Anav, Paternot, Vinu: Appreciate all the time you given me. You guys were a great help.

Hope Mikrotik wakes up.

ramesh, its not the MT, its your provider (ISP) doing something not standard or not giving you the correct information or not setting their end up properly.

[/quote]
ramesh, its not the MT, its your provider (ISP) doing something not standard or not giving you the correct information or not setting their end up properly.
[/quote]
Hi,
I don't think so they are a very big isp with more than a million customer across india.
there might be a small mistake across configuration or as we know about mikrotik and its steep learning curve.
Lets see what ramesh replies

vinu, I meant that the router works and its not a problem with the router. The configuration of the router is a completely different story and depends on the individual

vinu, I meant that the router works and its not a problem with the router. The configuration of the router is a completely different story and depends on the individual

Ha Ha yes absolutely

Sorry guys, you all were right with your trust in Mikrotik. It took another router, 2 more days and lot of sweat to knock my head into checking the cables again. Here's what happened:

1. Connected my new router hoping for a instant connection (just like my laptop). To my surprise the wan-connection light kept flashing just like the RB750.
2. Connected my laptop again and it worked like a charm. This time I decided to check the speed of connection, it turned out to be a 10mbps connect. (Wish I had checked this before).
3. Now I had no choice but to follow Paternot's advice. Trudged 2 floors down and opened the "my-fence" joint and connected my laptop directly there.
4. 100mbps connection here, proved there was a cable problem and also that it lay between here and "my-patch-panel" on 2nd floor. My old laptop has a 100mpbs nic.
5. But I had extensively tested the cable links using an off the shelf cable tester and everything appeared fine. So I suspected some signal loss issue.
6. Therefore I attached a POE powered ethernet extender at "my-fence" (luckily I have a POE switch near "my-patch-panel"). This did mean creating another link.
7. The ISP line, now connected through the signal extender, had to be attached to the POE port of my switch and laptop/router connected to another port on it. Also: These 2 ports had to be linked by configuring the switch.
8. After the switch was configured, I checked the connection speed again on the 2nd floor patch panel. This time the laptop connected at its max speed of 100mbps.
9. Disconnected the laptop and connected the "NEW" router which was still in place. PPPoe connection worked and ethernet was stable.
10. Disconnected "new" and put the RB750 back in place.
11. Lo and behold: full gbps link established, no flapping. PPPoE however did not work, but that did not seem a problem, now.
12. After some fiddling with the settings got the PPPoE up. Now things are back to normal even though I have more links in the connection to my ISP.
(Vinu: It took sometime for me to figure out that the DHCP client had to be enabled (not disabled on the interface connected to PPPoE) for the PPPoE to work,

Many thanks for your confidence and your valuable support guys. Happy to report without your help things would not have improved.

SORRY need to record one more clarification before closing this thread as solved.

VINU was RIGHT. After running the router for a few days i have to conclude that the
DHCP client on the interface linked to PPPoE must be disabled for a stable connection.

SORRY need to record one more clarification before closing this thread as solved.

VINU was RIGHT. After running the router for a few days i have to conclude that the
DHCP client on the interface linked to PPPoE must be disabled for a stable connection.

If you mean IP DHCP client, that makes sense because the Client work is done in the PPPOE section...........

Yes, that's right Anav.

Hi,
Enjoy ur mikrotik

Its truly a world community!