5520 stacking with QSFP+ to SFP+ adapter

[NN_QA]

Hi,

I am trying to stack my 5520 series switch, using QSFP+ to SFP+ adapter.But switch is not detecting  neighbour device and also tried to use the stack port as a normal ethernet port in that way also it is link is in down state only .Anyone hav any idea?

[NN_QA]

Hi stefan,

Yes i disabled stacking-support option.SFP got detected but link is not getting up.

Port speed tried to set 10G but getting one error 

Error: Auto negotiation is not supported on 10G SFP+ optics in port 25.

can you suggest me which qsfp and direct attach cable can use for stacking(part number of the material).?

Regards,

Nakul

[Stefan_K_ · Accepted solution]

Sounds like you configured it with auto on? Try: configure ports 25 auto off speed 10000 duplex full

Regarding stacking cable: you can use 10311, 10312, 10313 etc.
These are Direct-attach cables. 10311 is 0.5m, 10312 is 1m etc.

You can use https://optics.extremenetworks.com/EXOS/ to check it. Transceivers are also listed there, incl. an information if they support stacking. 10334 could be an option.

[Stefan_K_]

Hi @NN_QA 

1. Native stacking is only possible using QSFP (40G)

2. SummitStackV is at least possible using VIM-4X, but most certainly not using QSFP28 Port.
3. Why not using QSFP Direct Attach cables?
4. If you want to use them as Ethernet Ports you have to disable stacking-support. Did you do this?

If you already disabled stacking-support to use it as Ethernet Port:

• Is the SFP detected? (show ports xx transceiver information detail)
• Did you configure the Port speed to 10G? (configure ports xx auto off speed 10000 duplex full)
• Anything in the logs? (show log)

Btw, this was already discussed in your other thread. The final conclusion was:

Yes, you can stack 5520 using QSFP28 Ports. The question is, if we can also use these Ports if we use QSFP -> SFP+ Adapters. But I checked the StackingTool again and it says that a VIM-4X is required... So the answer is probably no.

---

Best regards
Stefan

[NN_QA]

Hi stefan,

#showlog
03/06/2024 07:59:07.10 <Erro:HAL.Stacking.Error> KICM LS Thread: SPB 2: Member [0,60]: Unable to read link status, error -18<Invalid port>

03/06/2024 07:59:07.09 <Erro:HAL.Stacking.Error> KICM LS Thread: SPB 1: Member [0,59]: Unable to read link status, error -18<Invalid port>

03/06/2024 07:59:07.09 <Erro:HAL.Stacking.Error> KICM BCM CB: SPB 2: Member [0,60]: Unable to read link status, error -18<Invalid port>

03/06/2024 07:59:07.09 <Erro:HAL.Stacking.Error> KICM BCM CB: SPB 1: Member [0,59]: Unable to read link status, error -18<Invalid port>

#sh ports transceiver information
25 21.14 -2.28 -26.78* 5.74 3.38 N/A

29 31.24 -2.42 -26.78* 8.77 3.34 N/A

#configure ports 25 auto off speed 10000 duplex full
Error: Speed specified is not supported on port 25.

regards,