Hi
Do you have VPC between Parent Switches & are you running VPC on dual homed FEX fabric ports. ?
If yes Below is the procedure,
1) boot the replacement switch without VPC, peer-links & FEX ports connected to it.
2) Make sure it has same Software version matches with the peer switch.
3) enable Pre-Provisioning for slots with appropriate FEX model.
, here find the guide:
http://www.cisco.com/en/US/partner/docs/switches/datacenter/nexus5000/sw/system_management/521_n1_1/b_5k_System_Mgmt_Config_521N11_chapter_0100.html#task_05BB53AD7AFB49CF9A8E4A5C6C37CB38
So, on the replacement switch you will pre-provision the Fabric Extender and configure the ports so it will be ready when you add the module to the RMA SW.
Please make sure you put the appropriate FEX model on the provision slot, otherwise, when connected it will not come Online
Example, FEX 110:
N5K(config)# slot 110
N5K(config-slot)#provision model N2K-C2248T
4) Now keep all ports at Shut down state Then Configure Entire switch that includes FEX host ports, FEX Fabric Ports & VPC peer-link, VPC Domain Configuration.
keep FEX host ports in shut state.
5) keep VPC Role priority on existing switch lower than , new switch
6) Connect Peer-link ports to Peer switch & wait till VPC Comes up-
7) Then connect Fabric ports from FEX to the pre-configured ports on replacement switch
After it comes online Unshut FEX host ports.
I got similar steps here as well
http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/operations/n5k_vpc_ops.html#wp425197
NOTE: I followed same process however, few ping drops were seen....arnd ( 5- 6 ping loss) only on few hosts...
Mazhar
