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fckruegel
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CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Wed May 20, 2020 1:09 pm

Hi;

I've got two CRS354-48G-4S+2Q+ and a Q+DA0001 QSFP+ Link Cable. I'd like to link both Switches via this QSFP+ case in order to have a single 40G link between these switches.
What is the correct way to group the four 10G interfaces of a QSFP+ port into a single port?

Thanks

Frank-Christian Kruegel
 
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mutluit
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Wed May 20, 2020 9:39 pm

Hi;

I've got two CRS354-48G-4S+2Q+ and a Q+DA0001 QSFP+ Link Cable. I'd like to link both Switches via this QSFP+ case in order to have a single 40G link between these switches.
What is the correct way to group the four 10G interfaces of a QSFP+ port into a single port?

Thanks

Frank-Christian Kruegel
You should ask the Technical Support whether the following cable (Q+BC0003-S+) can be used for that, or whether there is another such cable for this kind of task: https://mikrotik.com/product/q_bc0003_s ... ifications
But you already have 2 QSFP+ ports on each device (besides the 4 SFP+ ports). Are they not enough?
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Thu May 21, 2020 12:53 am

The OP does not want to break out, he just wants to connect to Q ports with the simple 40G DAC she has.

I think Mikrotik automatically configures the Q ports according to what you plug in.
Last edited by vortex on Thu May 21, 2020 2:16 am, edited 1 time in total.
 
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mutluit
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Thu May 21, 2020 1:54 am

The OP does not want to break out, she just wants to connect to Q ports with the simple 40G DAC she has.

I think Mikrotik automatically configures the Q ports according to what you plug in.
I understood it such that the OP wants to bundle the 4 SFP+ ports to a Q port.
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Thu May 21, 2020 2:16 am

No, he said he wanted to group the 4 components of the Q port into 40G.

With some other brands you would have to execute a command to split a Q port or to merge the components back.
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Thu May 21, 2020 6:20 am

No, he said he wanted to group the 4 components of the Q port into 40G.

With some other brands you would have to execute a command to split a Q port or to merge the components back.
Man, a Q port is already 40G, internally consisting of 4x 10G.
See also the Q cable with the 40G modules at each end: https://mikrotik.com/product/q_da0001
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Thu May 21, 2020 9:50 am

That is the cable that he has.

I don't know how the 40G port appears in the OS when you plug that cable in, I only saw a screenshot with it split.
 
fckruegel
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Fri May 22, 2020 4:52 pm

The problem is that the QSFP+ ports show up as four individual SFP+ interfaces. If I connect two switches with a QSFP+ cable, I've got 4 individual links. This might cause loops etc so only one link would be used. I need to tell the switch chips that these 4 links belong together. How do I do this so the switch hardware gets used and not the processor?

Frank-Christian
 
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mutluit
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Fri May 22, 2020 5:38 pm

The problem is that the QSFP+ ports show up as four individual SFP+ interfaces. If I connect two switches with a QSFP+ cable, I've got 4 individual links. This might cause loops etc so only one link would be used. I need to tell the switch chips that these 4 links belong together. How do I do this so the switch hardware gets used and not the processor?
My guess is that RouterOS already takes care of it. Not sure, but maybe it's even industry-standardized in exactly this way. So, then maybe you don't need to do anything. But to be 100% sure, you better should ask the Technical Support at https://help.mikrotik.com/servicedesk . Let us too know about the result :-)
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Sat May 23, 2020 6:06 am

It is not standard for a port to appear split when it is not used that way.
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Sat May 23, 2020 8:26 pm

It is not standard for a port to appear split when it is not used that way.
Yes, I too would not have expected such a splitted port as was described by the OP.
I personally have no experience with 40G yet, I only read sometime somewhere that 40G is physically realized by 4x 10G internally, but externally it should just be a single 40G port.
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Sat May 23, 2020 8:32 pm

Just plugging a 40G cable seems to be working as expected for some people. Maybe it is a teething bug.
Last edited by vortex on Tue May 26, 2020 4:20 pm, edited 1 time in total.
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Tue May 26, 2020 3:58 pm

I've linked two CRS354 with a a QSFP+ DAC-Cable plugged into the top QSFP+ port and rebooted both switches.
The port's interfaces show up as qsfpplus1-1 through qsfpplus1-4.
 
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Re: CRS354-48G-4S+2Q+ - how to link two of them via QSFP+

Tue May 26, 2020 4:26 pm

Is auto negotiation enabled on the ports?

It looks like "1" should appear as 40G and the others as down:

viewtopic.php?t=151451#p748227

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