Random Request Timeout with Lan switch

Configuration

My router: FRITZ!Box 6490 (manual)
Switch: Netgear GS205 (spec)

Internet:
Download 212 Mbit/s
Upload 12.7 Mbit/s
FRITZ!Box uses a DS Lite tunnel, IPv4 over DS Lite (Power Mode enabled 1 Gbit/s)
Ehternet Driver Internet/Dublex configured to: Auto Negation

Problem

Without switch I have no packet loss, but when I connect my PC (tried windows 10 desktop and Linux ubuntu Laptop) I'm getting random packets loss between 2% and 10%.

Ping statistics for 8.8.8.8:
Packets: Sent = 186, Received = 182, Lost = 4 (2% loss),
Approximate round trip times in milli-seconds:
Minimum = 14ms, Maximum = 89ms, Average = 19ms

When Im talking in skype/slack for example, packet loss increases

Ping statistics for 8.8.8.8:
Packets: Sent = 498, Received = 462, Lost = 36 (7% loss),
Approximate round trip times in milli-seconds:
Minimum = 13ms, Maximum = 134ms, Average = 18ms

Even when I pinging router

Ping statistics for 192.168.178.1:
Packets: Sent = 345, Received = 320, Lost = 25 (7% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 6ms, Average = 0ms

arp-a

Interface: 192.168.178.28 --- 0x3
Internet Address      Physical Address      Type
192.168.178.1         c8-0e-14-ac-9d-fb     dynamic
192.168.178.20        e0-b9-a5-ce-0f-b2     dynamic
192.168.178.27        5c-e0-c5-f3-e7-29     dynamic
192.168.178.53        a0-48-1c-5c-77-dc     dynamic
192.168.178.254       c8-0e-14-ac-9d-fc     dynamic
192.168.178.255       ff-ff-ff-ff-ff-ff     static
224.0.0.22            01-00-5e-00-00-16     static
224.0.0.251           01-00-5e-00-00-fb     static
224.0.0.252           01-00-5e-00-00-fc     static
239.255.255.250       01-00-5e-7f-ff-fa     static
255.255.255.255       ff-ff-ff-ff-ff-ff     static

I tried:

to change ethernet cabel
realese/renew ip
flush dns cache
restart router

Update 1: I replaced switch with other router and tried to use second router as switch. Packet loss gone. Can this switch be broken? Is there any way to test switch functionality?

What can cause packet loss in switch? Im really without any ideas..

Update 2: Interesting test:

After connecting: Main router (1Gbit/s) to other switch (100mbit/s) and to actual testing router (Netgear GS205 1Gbit/s) there is no request time outs.

Mindau

Posted 2017-01-21T16:13:28.177

Reputation: 71

run tests with and w/out the switch -- http://www.dslreports.com/speedtest or others -- look for bufferbloat or other problems. are all devices on the switch operating at 1Gbps? or are there devices on the switch that are running at 100Mbps?

– quixotic – 2017-03-05T13:37:25.037

Switch is 1Gbps, device is 1Gbps too. It has something with UDP connection,because skype always stucking.Event I ping successfuly other NIC, skype connection always time outs – Mindau – 2017-03-09T12:11:07.190

I suspect a hardware problem in the switch. Get rid of switch, use another switch. – dirkt – 2017-03-09T17:13:04.430

Note about your update2: if you can, try to test the original configuration (FRITZ!Box 6490 + Switch: Netgear GS205) at 100 and not at 1000. If the packet loss will drop you narrow your research field. Try to connect via wireless a computer at the maximum speed allowed (by Fritz...) and check if you have timeout issues. Try to download a huge file (maybe an iso) and check for the errors (and transfer speed). If the problem remains only when the 2 devices are connected at 1000 and disappears when a computer is directly (or via wireless) connected to Fritz you know where the problem is. – Hastur – 2017-03-12T11:11:49.610