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huge packets lost on full duplex

Posted: Fri Apr 21, 2017 9:03 pm
by mamemo25
Hi everybody, Im a bit noobish with networking and related topics(Im developer tbh), I have small network at one of my clients, this is the setup.

From one side I have router(T-com, seedport w724v) connected to mikrotik RB2011UiAS-2HnD-IN on eth1 port. then i have CAT6 100m long cable connected to Zyxel switch GS-105SV2 and then ethernet table connected to raspberry PI 3.

By the default mikrotik has enabled full duplex and half duplex for my network with auto configuration, when Im using that default settings and ping raspberry pi 10%+- of packets are getting lost, and connection is dropping every 1-2minutes on 10-12 seconds. When i changed connection type to half duplex 100mbit then it reduced packets lost to 2-3% and that connection lost is lasting for maybe 20ms and not 10-12 sec as before.

Can you help me with this problem, do I have to configure something, is the switch choice bad on other side? There is no huge data sending over the network(basic java app) so half duplex will make it i hope.

Thanks for the help and time.

BR

Re: huge packets lost on full duplex

Posted: Sat Apr 22, 2017 12:10 pm
by helipos
Best thing would be to rule out the Mikrotik.
Get a laptop and plug it in to that Zyxel switch and test back to the Mikrotik from there.

There could be a million things wrong here, but you need to rule something out unless you want to suspect everything.

Re: huge packets lost on full duplex

Posted: Sat Apr 22, 2017 1:35 pm
by mamemo25
ok but for now with half duplex 100M it is working ok, but i guess that is not the right solution.

Re: huge packets lost on full duplex

Posted: Sun Apr 23, 2017 10:06 am
by mamemo25
there is still 2-4% package lost, I will have to replace switch and try again, also put 2 switches instead of mikrotik maybe, but with full duplex packet lost is 10% and is repeating in same intervals, i guess that could also point to some problem?

Re: RE: Re: huge packets lost on full duplex

Posted: Sun Apr 23, 2017 11:11 am
by hengst
there is still 2-4% package lost, I will have to replace switch and try again, also put 2 switches instead of mikrotik maybe, but with full duplex packet lost is 10% and is repeating in same intervals, i guess that could also point to some problem?
When auto switches back to 10 and/or half duplex it tells you most of the time something is wrong with the cable connection. 100 meters CAT6 might be on the edge if capabillity here.

Verstuurd vanaf mijn D5803 met Tapatalk

Re: RE: Re: RE: Re: huge packets lost on full duplex

Posted: Sun Apr 23, 2017 11:16 am
by hengst
there is still 2-4% package lost, I will have to replace switch and try again, also put 2 switches instead of mikrotik maybe, but with full duplex packet lost is 10% and is repeating in same intervals, i guess that could also point to some problem?
When auto switches back to 10 and/or half duplex it tells you most of the time something is wrong with the cable connection. 100 meters CAT6 might be on the edge if capabillity here.

Verstuurd vanaf mijn D5803 met Tapatalk
https://en.m.wikipedia.org/wiki/Category_6_cable

Verstuurd vanaf mijn D5803 met Tapatalk

Re: huge packets lost on full duplex

Posted: Sun Apr 23, 2017 10:50 pm
by mamemo25
it is not auto switching, when it is on full duplex 10/100/1000 then packet lost is 10% +-, in same intervals, and i manually switched it to half duplex 100 and it works much better now, 2-4% packets lost, any idea now to improve signal, or test is it cable related, and CAT6 should go up to 100m right?

Re: huge packets lost on full duplex

Posted: Mon Apr 24, 2017 5:40 am
by 2frogs
Not all cable labeled as CAT6 is actually CAT6. I would try a shorter cable in the same port to rule out the Mikrotik. You might also check the ends and be sure they are not over/under crimped and check the cable path to be sure it is not in close proximity to electrical wires, light ballast, etc..

Re: huge packets lost on full duplex

Posted: Mon Apr 24, 2017 6:57 am
by idlemind
I agree there is a "should" go that far. It sounds like a layer 1 problem. It could be at any point (device or cable). The best thing to do is try to remove one component and test. That should help you narrow down the device or cable.

As far as the cable goes if you are in the US their are plenty of cabling companies that specialize in low voltage cabling like Ethernet. You may find it helpful to have one of them come test the cabling. Fluke makes a fantastic copper tester that can provide very in depth troubleshooting information. A lot of the specialty cabling companies have equipment like this to verify cable performance as part of cabling systems warranties. You can typically make a fairly cheap service call to them and they'll bring their test kit and verify the cable run and often can determine if the cable is fine but either end of the termination is at fault.

It may be very helpful. Think of how much your time and your clients time is worth. Sometimes a call to an expert for this kind of thing can help resolve an issue quickly and cheaper.

Re: huge packets lost on full duplex

Posted: Mon Apr 24, 2017 12:13 pm
by pe1chl
Make sure both sides are set to AUTO.
When one side is AUTO and the other is manually set to duplex, what you see is normal.
Never use manual configuration at one end only. Today, best is to not use manual configuration at all,
but when the other side insists it must be set to manual (usually due to "best practice" procedures established
15 years ago and never updated), you must do matching manual configuration as well.