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swapnilsonawane81090
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RX Drops on SFP+

Tue Mar 08, 2022 4:42 pm

Facing This issue on v6. also same on v7
now upgraded on v7.1.3 but still facing RX drops on the interface.
Image

This is Dell 620
16 Gig Ram 2 Xeon Processors (24 Cores) 2.5Ghz
2 SFP+ Ports
RouterOS is on SSD
Image
Multi Cpu = Checked
x86-64 = Checked
Connected using DAC Cable
Already Cleaned 10G LAN Card, tried to shift it to another slot, also tried to replaced it with newer one, But no luck

please help us to stop this packet dropping issue.
Last edited by swapnilsonawane81090 on Wed Mar 09, 2022 3:42 am, edited 1 time in total.
 
Zacharias
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Re: RX Drops on SFP+

Tue Mar 08, 2022 9:12 pm

How are those SFP ports connected ?
Using a DAC or AOC cable ?
 
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TomjNorthIdaho
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Re: RX Drops on SFP+

Tue Mar 08, 2022 11:15 pm

If you are using fiber , check your optical receive signal strengths ( on both sides ) then verify the sfp modules are within spec of the received signal strength. Also check the distance your sfps are rated for.
 
Zacharias
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Re: RX Drops on SFP+

Tue Mar 08, 2022 11:24 pm

If it is fiber, also check if you use the correct SFP modules along with the Fiber type used...
 
swapnilsonawane81090
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Re: RX Drops on SFP+

Wed Mar 09, 2022 3:41 am

Connected Via DAC Cable
 
swapnilsonawane81090
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Re: RX Drops on SFP+

Wed Mar 09, 2022 6:24 pm

*Also, it has tx drops on pppoe users *
every time the user logins 2 packet drops on tx.
 
r00t
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Re: RX Drops on SFP+

Wed Mar 09, 2022 7:51 pm

If it's really directly related to user logging it, then it looks like software issue.
Probably IO blocking causing issue in ROS... I can think of something like writing to flash on user login somehow stalls all IO or something like that... but that's just speculation.
But if it's really related to traffic, there is zero chance this is hardware issue (hardware packet loss would be more or less random).
Try to collect as much info from your router as possible and contact Mikrotik support... I think that's your only hope.
 
swapnilsonawane81090
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Re: RX Drops on SFP+

Thu Mar 10, 2022 4:18 pm

has anyone faced this issue in the latest ROS?
 
swapnilsonawane81090
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Re: RX Drops on SFP+

Wed Mar 16, 2022 3:42 pm

Mikrotik is totally irresponsible.
 
msatter
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Re: RX Drops on SFP+

Wed Mar 16, 2022 7:05 pm

SFP(+) just drops a lot also under v6. Many topics about that and we just live with it.
Screenshot_20220316_180257.jpg
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swapnilsonawane81090
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Re: RX Drops on SFP+

Thu Apr 21, 2022 4:43 am

Facing This issue on v6. also same on v7
now upgraded on v7.1.3 but still facing RX drops on the interface.
Image

This is Dell 620
16 Gig Ram 2 Xeon Processors (24 Cores) 2.5Ghz
2 SFP+ Ports
RouterOS is on SSD
Image
Multi Cpu = Checked
x86-64 = Checked
Connected using DAC Cable
Already Cleaned 10G LAN Card, tried to shift it to another slot, also tried to replace it with a newer one, But no luck

please help us to stop this packet dropping issue.
@mikrotik please reply
 
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chechito
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Re: RX Drops on SFP+

Thu Apr 21, 2022 4:56 am

maybe try changing interface queue for a big pfifo queue type
 
NickOlsen
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Re: RX Drops on SFP+

Mon Apr 25, 2022 6:37 pm

It's very likely that you are seeing buffer overflow. The packet is coming in that interface, attempting to enter the queue to be picked up by the kernel and cannot enter it because it's full (so it must be dropped). Multiple hardware queues help balance this over multiple cores better. Make sure your ethernet card has multiple hardware queues (System > Resources > IRQ). If it doesn't, get a different NIC that does.

Assuming it does have multiple hardware queues, you can also add a bigger buffer in the OS. I'd recommend setting the interface to "Multi-Queue-Ethernet-Default" under Queue > Interface Queue.

Then raise the queue size under Queue Type by ~100 packets until the drops stop. Do note however that the tradeoff will be latency for some packets. Which the buffer gets really large (Because the CPU can't pick the packets up fast enough) the packets that are in the buffer will incur a higher latency. But you may not notice or even be able to measure it decently without serious lab equipment.

This is one of the downfalls of MT and ultimately is why we're moving to big iron soon. MT fits certain needs. But not all.
 
swapnilsonawane81090
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Re: RX Drops on SFP+

Sat Apr 30, 2022 6:14 am

It's very likely that you are seeing buffer overflow. The packet is coming in that interface, attempting to enter the queue to be picked up by the kernel and cannot enter it because it's full (so it must be dropped). Multiple hardware queues help balance this over multiple cores better. Make sure your ethernet card has multiple hardware queues (System > Resources > IRQ). If it doesn't, get a different NIC that does.

Assuming it does have multiple hardware queues, you can also add a bigger buffer in the OS. I'd recommend setting the interface to "Multi-Queue-Ethernet-Default" under Queue > Interface Queue.

Then raise the queue size under Queue Type by ~100 packets until the drops stop. Do note however that the tradeoff will be latency for some packets. Which the buffer gets really large (Because the CPU can't pick the packets up fast enough) the packets that are in the buffer will incur a higher latency. But you may not notice or even be able to measure it decently without serious lab equipment.

This is one of the downfalls of MT and ultimately is why we're moving to big iron soon. MT fits certain needs. But not all.
Changed to this ("Multi-Queue-Ethernet-Default" )
Still facing drops.
 
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chechito
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Re: RX Drops on SFP+

Sat Apr 30, 2022 5:22 pm

what percentage of the total received frames are rx-drop ??

rx-drop are permanent/periodic or only when there is a surge in traffic ?
 
swapnilsonawane81090
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Re: RX Drops on SFP+

Sat Apr 30, 2022 6:20 pm

what percentage of the total received frames are rx-drop ??

rx-drop are permanent/periodic or only when there is a surge in traffic ?
No.
They are random, & now we are also having Rx Errors increasing 2 or 3 every 3rd or 4th sec.
 
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z4ki
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Re: RX Drops on SFP+

Sat Apr 01, 2023 10:22 am

Hello, did you manage to solve this?
I'm facing similar issue.

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