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Network instability - issue learning/remembering routes

Posted: Fri Jul 10, 2009 10:42 am
by Wyz4k
Hi there,

We are using an RB1000. Our lan network is connected on ether 1 (192.168.1.141), an ADSL router is connected to ether 3 (192.168.2.141) and an ADSL router is connected to ether 4 (192.168.4.141). There is also an ADSL router connected on ether 1 as to allow PPPOE connections from PC's on the LAN network. (Ideally I would want to move this router to ether 2 but I have not been able to get bridging working through different RB ethernet ports)

The RB1000 is configured as the default gateway on all the PC's in the network, but the PC's do not get their IP's from the RB1000. The IP's get assigned by a linux dhcp server.

We are experiencing the following problems sporadically: Connections to other machines on the LAN network get interrupted. If I ping the machine during these times I get a reply from 192.168.4.141 (destination host unreachable). I get this while pinging a machine in the 192.168.1.0/24 subnet from a machine in the same subnet. The problem usually fixes itself in a few minutes, or I can force it by connecting to the RB1000 via winbox and then having the RB ping the machine I am trying to connect to. The RB's first 3 or 4 pings might time out, but thereafter it receives replies and the connection between the two machines suddenly work again.

How can I fix the sporadic routing issue?
Why do I get a host unreachable reply from 192.168.4.141 and not 192.168.1.141?

The RB is also used to separate local and international traffic and use different routes for each. I have attached jpgs of the route list rules.

We are using the latest stable release of Router OS 3.25 on the RB1000.

Any assistance will be appreciated.

Re: Network instability - issue learning/remembering routes

Posted: Fri Jul 10, 2009 4:31 pm
by thiele
Hi,

Look at your second screenshot, specially to selected route. You really need it? 192.168.1.0/24 is not
connected to your board (DAC just after selected one)? And... you are routing 192.186.1.0/24 through 2 interfaces? ether1 and eth... Maybe that's the point, when mikrotik use a wrong interface you cannot reach right destination.

I saw the LAN routing mark, but don't got why you use that.



Jorge

Re: Network instability - issue learning/remembering routes

Posted: Sun Jul 12, 2009 8:51 pm
by Wyz4k
Look at your second screenshot, specially to selected route. You really need it? 192.168.1.0/24 is not
connected to your board (DAC just after selected one)? And... you are routing 192.186.1.0/24 through 2 interfaces? ether1 and eth... Maybe that's the point, when mikrotik use a wrong interface you cannot reach right destination.
Thanks for the reply! I also saw that, but the 2nd part of "ether1, eth..." is also ether1. It's just a route I added for the routing mark LAN. It was an attempt from my side to fix the problem. But clearly it isn't helping much. I can't modify the "ether1, ether1" field.... it's automatically populated for me.

Re: Network instability - issue learning/remembering routes

Posted: Sat Jul 25, 2009 11:19 pm
by Wyz4k
*bump*

Re: Network instability - issue learning/remembering routes

Posted: Wed Aug 05, 2009 9:09 am
by Wyz4k
Hi there,

We are using a RB1000 and have upgraded to 3.27, however the problem still persists. I created a supout file as soon as I saw the problem, but it only lasted a few seconds. I hope it contains the necessary information to fix the problem.

We will soon be purchasing several more RB's but will wait until this issue has been fixed before adding extra complexity to the network.

Thanks in advance,
Dewald

Re: Network instability - issue learning/remembering routes

Posted: Wed Aug 05, 2009 4:44 pm
by Chupaka
please send supout.rif to support@mikrotik.com - it's useless here, on the forum

Re: Network instability - issue learning/remembering routes

Posted: Wed Aug 05, 2009 4:51 pm
by gmsmstr
I would suggest taking the advice from the forum, or hiring a consultant on the MT consultant list. I'm sure they can get you squared away in no time.

Re: Network instability - issue learning/remembering routes

Posted: Wed Aug 05, 2009 6:29 pm
by Wyz4k
Thanks for the tips.

I have submitted it via email as well, with the necessary supporting info.

Which advice exactly gmsmstr?

I would expect the answer to the question on the reply from ..4.1 to be quite easy to fix, yet no-one has been able to give any advice in this regard?

I would prefer to exhaust all options before hiring a consultant to fix the problem. This is an erratic issue and it could be difficult for the consultant to find.

D