Nexus 3000

[adamgibs7]

Dears

we purchased Cisco Nexus 31108TC-V Switch with CVR-QSFP-SFP10G adapters to convert 40G into 10G, also i ordered 4 nos SFP+ LR (10Gbase-LR) which will be inserted in the CVR-QSFP-SFP10G adapters for connecting to servers.

I have 2 small simple question and a doubt

By the below output i can see that i can use either of them but i want to use 10G as a breakout so i will choose portmode (48x10g+4x100g+2x40g ) but according to the attached it is port-mode 2, Please confirm is it correct

switch(config)# hardware profile portmode ?
  48x10g+4x100g+2x40g  Line rate cut through mode
  48x10g+6x100g        48x10G+6x100G oversubscribed port mode

Question II:

If have done the breakout by the command interface breakout module 1 port 53 map 10g-4x this has created multiple interface as 1/53/1, 1/53/2,1/53/3,1/53,4  only 1 port will be used from the parent interface i.e 1/53/1 in my case becz i will be connecting from  SFP+ LR (10Gbase-LR) which will be inserted in CVR-QSFP-SFP10G adapter connecting to the server, Ifincase i would have a DAC cable then i would have used other ports as well 1/53/2,1/53/3,1/53/4 from that QSFP, so on this port only 1 server will be connected and for other 3 servers i will connect on 1/51/1 and 1/52/1,1/54/1 ,,

please correct me if i m wrong.

thanks

Thannks

[Rick1776]

What version of NX-OS are you running? It has to be NXOS 7.0(3)I4(1)

These are the following two port modes are supported for that switch


48x10GBASE-T ports + 6x100G QSFP ports.
48x10GBASE-T ports + 4x100G QSFP ports + 2x40G QSFP ports.
The following features are specific to port mode-1:
10GBASE-T Ports 1 through 8 always delivers at line-rate.
10GBASE-T Ports 9 through 48 are always over subscribed.
QSFP Ports 49 through 52 are capable of 100G and/or 40G and 10Gx4 breakout.
QSFP Ports 53 through 54 are capable of 100G and/or 40G. These ports do not support 10Gx4 breakout.
The maximum supported port count is 64x10G + 2x40G/100G.
The following features are specific to port mode-2:
10GBASE-T Ports 1 through 48 always delivers at line-rate and support cut-through switching.
Line-rate SFP+ ports support cut-through switching and because of that it will have less latency.
QSFP Ports 49 through 52 are capable of 100G/40G and 10Gx4 breakout.
QSFP Ports 53 through 54 are capable of 40G and 10Gx4 breakout. These ports do not support 100G.
The maximum supported port count is 72x10G.

[adamgibs7]

Dears,

I got the key thing,

To use SFP+ 10 LR we have to use the same breakthroguh command interface breakout module 1 port 53 map 10g-4x this will connecte single SFP to the server leaving the other three ports free and if i would have DAC cable i would have used all the four but inetead i m usiing the normal LC-LC fiber cable.

Thanks

[Rick1776 · Accepted solution]

That is correct. Please remember that LR stands for Long Reach witch is Single-Mode fiber.

Please see the attached picture.

[adamgibs7]

Dears,

I am using port mode 2 as per the attched , in which i can get 4X 100G/40G ( which can be breakout 10X4) +2X40G=10X4 breakout ,

when i try to breakout port 49 into 10GX4 it breaksout the command is accepted but when i connect it doesnt come up i am connecting through a cable SFP-H10GB-CU5M= , the same cable when it is use for port 54 with a breakout command it works fine.

Anybody can help to understand what can be the issue

Thanks

[Rick1776]

Hmm, sounds like the switch could be bad port on the switch. Can you plug it into another port to see if that works. Also try to connect end to end via port 49-50 to see if the interfaces come up.

Can you send the "show interface" output and "show interface transceiver".

[Rick1776]

After you entered the command interface breakout module 2, did the module reload?

[adamgibs7]

Dears,

I want to update the thread of the post , i reloaded the switch and the interface come up this is becz i think i entered the breakout commnad for port 49 and then revert it back after that i again entered the command and it didnt worked

so before reloading i entered no interface breakout command for the port and reloaded the switch when the switch came up then again i entered the interface breakout command for the port and the all the 4 interfaces were up.

strange is that no logs in the buffer when i do sh logging i dont see any error logs

[Rick1776]

Well I’m just glad you where able to get it working.  What command did you use for the breakout?

[adamgibs7]

Dear Rick,

no interface breakout module 1 port 49 map 10G-4X and then i rebooted, after rebooting i applied the below command interface breakout module 1 port 49 map 10G-4X,

I think some NX-OS glitch