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tberg
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CRS Ethernet TX Drops

Sun Feb 16, 2020 10:44 pm

We recently installed a few CRS317 and 328P switches. I am noticing TX Drops incrementing on some Ethernet interfaces. What are TX drops? Are they buffer overflows or filtered traffic with incorrect/unallowed VLAN tags?
 
tberg
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Re: CRS Ethernet TX Drops

Mon Feb 17, 2020 3:57 pm

Looking closer, they must be buffer overruns. They are only happening on 1G ports on switches that have 10G ingress and multiple 1G egress. I assume you cannot change interface queue type without breaking hardware offload.
 
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Re: CRS Ethernet TX Drops

Mon Feb 17, 2020 4:26 pm

If you are going to be moving a lot of traffic between ports at different speeds , you may be exceeding the buffer (which is required for moving traffic between ports of different speeds.
 
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Re: CRS Ethernet TX Drops

Mon Feb 17, 2020 6:14 pm

Thanks! Yes I'm sure that is it. On the worst port, it is about .1%. We're moving to switch centric architecture and upgrading routers. Once routers are all 10G, part of the problem should go away. However, it's got me thinking about uplink to access switches with 1G backhaul and APs. It might be better to aggregate a few 1G uplinks vs. 10G uplink. Either that or get different switches with bigger buffers?
 
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Maggiore81
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Re: CRS Ethernet TX Drops

Thu Apr 02, 2020 6:30 pm

Hello
we replaced an UBNT Edgeswitch (all with 1G) ports with a CRS326-24G-2S+ with RouterOS
we just use for VLANS, as a L2 switch.

we replaced the UBNT to take advantage of the S+ ports 10G.
We have now a 10G SFP+ port with DAC to the router (CCR 1009).

We have multiple PTP Wireless licensed uplink coming at 1G speed into the switch, and going aggregated in a VLAN TRUNK port on the CCR through 10G port.
we noticed immediately tx drops.
Is normal or should we change something?
 
hero12
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Re: CRS Ethernet TX Drops

Tue Oct 13, 2020 2:50 pm

Have same problem with no answear. :(
 
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andrewe02000
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Re: CRS Ethernet TX Drops

Wed Dec 30, 2020 1:16 am

I have the same problem and opened a ticket with no response over 2 weeks ago. Very annoying. The odd thing is that im only getting the tx drops on the interface going to my elan. At first I thought it was an mti mismatch but have since ruled that out. I even put a CRS309 in between my ELAN and my CCR2004 and the tx drops moved to the interface going to the ELAN on the CRS309 and stoped on my cloud core. I've tried finisar, mikrotik, and fiberstore modules with the same results. Even tried a 1G and 10G DAC from multiple vendors. My ISP for my ELAN checked their equipment and show no drops on their side or FCS errors. It's odd that the problem moved down to the interface on my CRS309 instead of staying on my CCR2004. Even odder is when I unplug the 10G DIA and switch over to my backup 1G DIA the TX drops go away and as soon as I plug my 10G DIA back in they come back. It is weird that the TX drops only show up once you open the interface and not in the column view when I select them. It always shows 0 in the column view on both the crs2004 and crs309 depending on whether or not im using the crs309 inline but shows up after double clicking the interface and going to stats. The other weird thing is that the tx drops don't show up on any other 1G interface on the CCR2004. I would expect it to be consistent at the very least. I set a lab up with all the smae routers and have yet to be able to reproduce the result in the lab and I believe this to be due to the fact that I am not able to tax the CPU load high enough to perturbate the issue. Please Mikrotik. HELP!!!!! My CCR2004 like many others is a paperweight as it is causing out of order packets and voice quality issues even thought the packet loss through the ccr2004 is low at 0.08 to 0.12 percent.
 
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Maggiore81
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Re: CRS Ethernet TX Drops

Fri Jan 01, 2021 11:34 am

I replaced the 2004 with 1036+10g edgeswitch XP from ubnt.
it is not an ideal solution, but the packet loss of the 2004 is unbearable.
I am going to rma everyone of them

i see packet loss also on RJ01 on them.
 
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andrewe02000
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Re: CRS Ethernet TX Drops

Mon Jan 11, 2021 8:51 pm

I replaced the 2004 with 1036+10g edgeswitch XP from ubnt.
it is not an ideal solution, but the packet loss of the 2004 is unbearable.
I am going to rma everyone of them

i see packet loss also on RJ01 on them.
I just sent my RMA request as well to ISPSupplies.com as well. Maybe I can get a Festivus miracle and they'll release a patch the day before I return the units. With my luck the day after I return them. Heaven forbid they communicate with customers and at least acknowledge the issue and let us know they are working on a fix or ROS7 release is imminent with a fix.... Something... Anything would be appreciated.