Nexus 1000v port-channels questions

Question

Hi,
I’m running vCenter 4.1 and Nexus 1000v and about 30 ESX Hosts.
I’m using one system uplink port profile for all 30 ESX Host; On each of the ESX host I have 2 NICs going to a Catalyst 3750 switch stack (Switch A), and another 2 NICs going to another Catalyst 3750 switch stack (Switch B).
The Nexus is configured with the “sub-group CDP” command on the system uplink port profile like the following:
port-profile type ethernet uplink
vmware port-group
switchport mode trunk
switchport trunk allowed vlan 1,800,802,900,988-991,996-997,999
switchport trunk native vlan 500
mtu 1500
channel-group auto mode on sub-group cdp
no shutdown
system vlan 988-989
description System-Uplink
state enabled
And the port channel on the Catalyst 3750 are configured like the following:
interface Port-channel11
description ESX-10(Virtual Machine)
switchport trunk encapsulation dot1q
switchport trunk native vlan 500
switchport trunk allowed vlan 800,802,900,988-991
switchport mode trunk
switchport nonegotiate
spanning-tree portfast trunk
end
interface GigabitEthernet1/0/18
description ESX-10(Virtual Machine)
switchport trunk encapsulation dot1q
switchport trunk native vlan 500
switchport trunk allowed vlan 800,802,900,988-991
switchport mode trunk
switchport nonegotiate
channel-group 11 mode on
spanning-tree portfast trunk
spanning-tree guard root
end
interface GigabitEthernet1/0/1
description ESX-10(Virtual Machine)
switchport trunk encapsulation dot1q
switchport trunk native vlan 500
switchport trunk allowed vlan 800,802,900,988-991
switchport mode trunk
switchport nonegotiate
channel-group 11 mode on
spanning-tree portfast trunk
spanning-tree guard root
end
Now Cisco is telling me that I should be using MAC pinning when doing a trunk to two different stacks , and that each interface on 3750 should not be configured in a port-channel like above,  but should be configured as individual trunks.
First question: Is the above statement correct, are my uplinks configured wrong?  Should they be configured individually in trunks instead of a port-channel?
Second questions: If I need to add the MAC pinning configuration on my system uplink port-profile can I create a new system uplink port profile with the MAC pinning configuration and then move one ESX host (with no VM on them) one at a time to that new system uplink port profile? This way, I could migrate one ESX host at a time without outages to my VMs. Or is there an easier way to move 30 ESX hosts to a new system uplink profile with the MAC Pinning configuration.
Thanks.

Answer 1

Hello,
From what I understood, you have the following setup:
     - Each ESX host has 4 NICS
     - 2 of them go to a 3750 stack and the other 2 go to a different 3750 stack
     - all 4 vmnics on the ESX host use the same Ethernet port-profile
          - this has 'channel-group auto mode on sub-group cdp'
     - The 2 interfaces on each 3750 stack are in a port-channel (just 'mode on')
If yes, then this sort of a setup is correct. The only problem with this is the dependance on CDP. With CDP loss, the port-channels would go down.
'mac-pinning' is the recommended option for this sort of a setup. You don't have to bundle the interfaces on the 3750 for this and these can be just regular trunk ports. If all your ports are on the same stack, then you can look at LACP. The CDP option would not be supported in the future releases. In fact, it is supposed to be removed from 4.2(1)SV1(2.1) but I still see the command available (ignore 4.2(1)SV1(4) next to it) - I'll follow up on this internally:
http://www.cisco.com/en/US/docs/switches/datacenter/nexus1000/sw/4_2_1_s_v_2_1_1/interface/configuration/guide/b_Cisco_Nexus_1000V_Interface_Configuration_Guide_Release_4_2_1_SV_2_1_1_chapter_01.html
For migrating, the best option would be as you suggested. Create a new port-profile with mac-pinning and move one host at a time. You can migrate VMs off the host before you change the port-profile and can remove the upstream port-channel config as well.
Thanks,
Shankar