Hi,
Sorry got busy and just last night had some time to test this again. I made sure the same vlans existed on both sides. I also limited the vlans that were on the trunk, no luck. Below are the latest configs I was using. Same thing, cisco ports would show a spanning tree negotiation in the form of amber ports for some time, the link would come up for about 3 seconds then shut down. I also tried setting the cisco side to a static port channel by using "channel-group 1 mode on" this did not help.
--= Cisco 3750 config =--
spanning-tree mode pvst
interface FastEthernet1/0/21
description Uplink to Aruba
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,8,10,21,22,23,24
switchport mode trunk
channel-group 1 mode passive
!
interface FastEthernet1/0/22
description Uplink to Aruba
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1,8,10,21,22,23,24
switchport mode trunk
channel-group 1 mode passive
interface Port-channel1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1
switchport mode trunk
--= Aruba s3500 Config =--
spanning-tree
mode pvst
interface-profile switching-profile "Trunk Port"
switchport-mode trunk
trunk allowed vlan 1,8,10,21-24
interface-profile lacp-profile "3750"
group-id 1
mode active
interface gigabitethernet "1/0/34"
enet-link-profile pc_default
lacp-profile "3750"
interface gigabitethernet "1/0/35"
enet-link-profile pc_default
lacp-profile "3750"
interface port-channel "1"
switching-profile "Trunk Port"
enet-link-profile pc_default