Configure Uplinks from my Dell TOR switches to Cisco Core switchs

Hello,

For a project of VSAN, I used this configuration to connect my TOR switches DELL S4128T-ON to the client core switchs 3560: 

#ConfigureVLT
interface ethernet1/1/25
description VLTI
no switchport
no shutdown
-----
interface ethernet1/1/26
description VLTi
no switchport
no shutdown
------
vlt-domain 100
backup destination XXXX
discovery-interface ethernet1/1/25-1/1/26
peer-routing
end
write memory

#ConfigureUplinks_To_Core
interface port-channel 100
description ToCore1

switchport access vlan 1
switchport mode trunk
switchport trunk allowed vlan 60,70
no shutdown

interface ethernet1/1/27
description ToCore1
channel-group 100 mode active
no shutdown

interface ethernet1/1/28
description ToCore1
channel-group 100 mode active
no shutdown
end
write memory

but there is no connection between the dell and the cisco in the port channel, and if i try access port i can ping between the switchs.

Any difference between native vlan in CISCO and DELL ?  Any Help ?