Nexus Fabric Extenders, config mismatch between downstream 5Ks?

[johnnylingo]

I'm evaluating the Nexus 2248TP Fabric Extenders as replacement for our older 3750E and 2960 switches.  I have the 2248 uplinked to a pair of 5548s, both switches report the Fex "online" and successfully bundled the ports in to a vPC.  Everything seems to work fine.

Where I'm confused on is configuration - since this is not shared between the 5548s, what is the source of truth for a port configuration on the Fex with there is disagreement?   For example, given this configuration...

N5548-1# show run int e116/1/1

version 7.0(8)N1(1)

interface Ethernet116/1/1
  switchport access vlan 111
  spanning-tree port type edge

N5548-2# show run int e116/1/1

version 7.0(8)N1(1)

interface Ethernet116/1/1
  switchport access vlan 222
  spanning-tree port type edge

Will this port be in vlan 111 or vlan 222? 

[Reza Sharifi]

When you dual home your FEXes to  2 5ks, in order for the ports to work correctly they must have identical configs on both switches. So, the config you posted should not work.

5548-1# show run int e116/1/1

version 7.0(8)N1(1)

interface Ethernet116/1/1
  switchport access vlan 111
  spanning-tree port type edge

N5548-2# show run int e116/1/1

version 7.0(8)N1(1)

interface Ethernet116/1/1
  switchport access vlan 111
  spanning-tree port type edge

HTH

[johnnylingo]

Well yes, but is there a way to guard against this, or auto-sync the configuration between the 5ks?

[Reza Sharifi]

Yes, you can use config sync, so you don't have to do it manually.

here is a link to it

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/operations/n5k_config_sync_ops.html

HTH