Connection fex N2K-C2232PP-10GE to a Nexus 7000

[Joris Deprouw]

Hi All,

I have a question concerning a N2K-C2232PP-10GE .

We have 2 nexus 7000 chassis with several N2K-C2248TP-1GE fexes. Now we want to connect a N2K-C2232PP-10GE .

What's the correct way to connect this type of fex. The same manner as a N2K-C2248TP-1GE?

Since vpc with a fex is not yet possible on the nexus 7000. We would have to connect the fex on a single chassis.

Like the other fexes I would like to connect it to 2 different line cards (N7K-F248XP-25) in the same N7K chassis.

Do I use 4 ports on the first N7K-F248XP-25 card and 4 on the second N7K-F248XP-25 card? Linked to 8 ports on the N2K-C2232PP-10GE? We have 8 twinax cables for uplink.

Thanks for your help,

Best Regards,

Joris

[nikolasgeyer]

Hi Joris,

The same connectivity rules apply for the 2232PP as the 2248TP. Specifically for F2 modules, you should connect the same amount of uplink ports across per port-group on the F2 module.

If you want to spread it across two F2 modules, I would personally connect it as follows:

Fex uplink ports 1 & 2 -> N7K F2 module 1, port group 1

Fex uplink ports 3 & 4 -> N7K F2 module 2, port group 1

Fex uplink ports 5 & 6 -> N7K F2 module 1, port group 2

Fex uplink ports 7 & 8 -> N7K F2 module 2, port group 2

That will give you protection against an entire F2 module failure, and also failure of an ASIC on a single F2 module. Don't connect all FEX uplinks to the same port group on the F2 module if you can avoid it, otherwise you can become succeptible to network disruption if there is an issue with the ASIC for that port group (and it does happen).

Cisco have a good document containing information about connecting FEXs to the N7K, including recommended connectivity, at http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus2000/hw/installation/guide/nexus_2000_hig/overviewN7K.html

[Joris Deprouw]

Nikolas,

Thanks for your feedback.

Not sure I can connect them all to a different port-group. But I'll try.

Best Regards,

Joris

[Joris Deprouw]

Hi Nikolas,

I'm trying to configure the fex uplinks like this to the fex.

module 6/33-34 and 6/37-38

module 7/33-34 and 6/37-38

If I'm not mistaken port 33 and 34 are port 1 and 2 of port-group 9 and port 37 and 38 are port 1 and 2 of port-group 10, so creating the uplink on these ports should work.

However I can put port 33 and 34 in the port-channel, when I add port 37 in the port-channel I get the message below.

NEXUS(config-if)# int e 6/37
NEXUS(config-if)# switchport mode fex-fabric
NEXUS(config-if)#   fex associate 155
NEXUS(config-if)#   channel-group 155
 Fex connectivity must be symmetric across all the port groups. Port group is a collection of 4 contiguous ports starting with port 1. Port indices across port groups must match. If port(s) {1,3} are used in port-group 1 same port(s) must be used in other port-groups. Multiple FEX can share a port-group. FEX uplinks can be connected to multiple different F2 LC as long as previous is met. Use command 'show interface ethernet <module-num>/ <port-num> capabilities' to check port-group members information
Port incompatible with FPC ('force' option can not overcome incompatibility)

Adding port 6/35 and 36 is no problem. Am I missing something?

Thanks,

Best Regards,

Joris

[Joris Deprouw]

Hi All,

I think I found the problem. I was hitting bug CSCuh86771 "Cross-Module Fex Fabric Po must be created in range"

You have to create the port-channel in 1 time with the range command.

so int e6/33-34,e6/37-38,e7/33-34,e7/37-38

then apply the configuration.

Best Regards,

JOris

[Muhammad Thanveer]

Hello,

If we apply the config as per the above range, it goes in to the same port-group right?

Can we put the 4 ports in one port-group and the other in the other port-group for the same fex?

Or do u meant that we must put all together in same port-group.

BR

Thanveer

[billmcgowan2]

That was it - Thanks!

[Muhammad Thanveer]

I have done it in this way, should work for you.

[Joris Deprouw]

Hi Thanveer,

This works for me too.

But I have 8 uplinks to configure and want to configure them over 2 modules and over 2 different port-groups per module.

So 4 ports per module, but not on the same asic (port-groups).

Thanks,

Br,

Joris