Nexus 7K Allocate M1 to F2e

[Mokhalil82]

Hi

I have a Nexus 7010 with an F2e module in a single VDC which is performing both routing and switching.

I also have a M1 module that is in a separate VDC but totally unused.

I want to allocate the M1 ports to the F2e VDC, which I understand will make the F2e operate at L2 and the M1 will be doing the L3 for the VDC so I will need to move my routed ports onto the M1 module.

Is there any other gotchas to be aware of when reallocating the ports to the F2e module?

Thankyou

[Paul Chapman · Accepted solution]

Hi -

I don't believe that you will have to convert your F2e-based routed ports to switchports.

The key in this situation is that you will incur an inefficiency in traffic forwarding.  When mixing F and M cards in the same VDC any traffic that requires L3 services will be transferred off the F card to the M card.  If your ingress and egress ports are on F cards, then you end up forwarding across the backplane fabric at least twice for any given packet.

You can easily test this by giving an unused F-port group (yes, you have to do 4 ports at a time) to the M VDC and verifying that you can issue the "no switchport" command.  Once you've confirmed the behavior, you can do your M-port move.

PSC

[Mokhalil82]

Thanks Paul.

After I move all my M1 ports to the F2e VDC, I want to move my L3 links between the nexus switches and the 2 x L3 links going out into the MPLS onto the M Module to avoid this inefficient packet forwarding. Then leave all my L2 links on the F2e such as VDCs and links to the Fex's.

What I am not sure bout at htis point is that, the M1 (N7K-M132XP-12L) only supports 10G and only works with 10G SFPs. Will me terminating my 1G links to the MPLS (1 X copper, 1 x fiber) on this module still work using a 10G SFP still work as I have a few 10G SFPs lying around.

I understand I only have 1G out to the MPLS but would that work?

Thanks

[Paul Chapman · Accepted solution]

Hi -

1. Based on all the spec sheets I can find on your particular M card, you are right that it only supports 10Gb connections.  If you attempt to insert a 1G SFP module the switch will mark it as "Invalid" and shut the port down.
2. The inefficiency that you get from passing traffic across the fabric will be in the form of a few nanoseconds of latency.  This is really only important if you are passing enough traffic across the fabrics to put them close to their limits.  (2) 1G MPLS connections will no noticeable impact.  I don't think that you should worry about this.  This problem is generally discussed in the scalability guides where the limits of the device are being pushed.  A typical business deployment will never get close to the system limits.

PSC