Trunk link issues between Cisco 6509 and Juniper EX2300

[Linak25]

I'm configuring a trunk between a Juniper EX2300 and a C6509, the trunk forms when I use 'nonegotiate' on the Cisco side however our standard is 'Dynamic Desirable' for all access layer devices and when I set this on the Cisco port-channel I get the following error after a short period.

%EC-SW1-5-CANNOT_BUNDLE2: Gi1/4/13 is not compatible with Gi1/4/13 and will be suspended (trunk mode of Gi2/4/13 is access, Gi1/4/13 is trunk)
%EC-SW2_STBY-5-CANNOT_BUNDLE2: Gi2/4/13 is not compatible with Gi1/4/13 and will be suspended (trunk mode of Gi2/4/13 is access, Gi1/4/13 is trunk)

My port-channel then gets suspended and I loose connection to the EX2300, till I configure the Cisco with nonegrotiate, 

Cisco 6509
=================
interface GigabitEthernet1/4/13
description Juniper access test
switchport
switchport trunk native vlan 3
switchport mode dynamic desirable
channel-protocol lacp
channel-group 11 mode active
!
interface GigabitEthernet2/4/13
description Juniper access test
switchport
switchport trunk native vlan 3
switchport mode dynamic desirable
channel-protocol lacp
channel-group 11 mode active
!
interface Port-channel11
description Juniper Access Test Switch
switchport
switchport trunk native vlan 3
switchport mode dynamic desirable
logging event link-status
logging event bundle-status
logging event spanning-tree status
end

Juniper EX2300
===============
root@JTTest> show configuration interfaces ge-0/1/1
speed 1g;
link-mode full-duplex;
ether-options {
802.3ad ae0;
}
root@JTTest> show configuration interfaces ge-1/1/1
speed 1g;
link-mode full-duplex;
ether-options {
802.3ad ae0;
}
root@JTTest> show configuration interfaces ae0
description "C6509";
native-vlan-id 3;
aggregated-ether-options {
link-speed 1g;
lacp {
active;
periodic slow;
}
}
unit 0 {
family ethernet-switching {
interface-mode trunk;
vlan {
members all;
}
}
}

I welcome any thoughts or pointers, thanks.

[MHM Cisco World]

not all vendor use DTP like cisco 
so disable it and config trunk mode directly is better
MHM

[M02@rt37]

Hello @Linak25 

DTP is disabled on Trunk link beween my Juniper EX4200 and Cisco Switch. 

It causes conflict like this.

[Linak25]

Thank you for the responses, what baffles me is that it worked perfectly fine for a few weeks and after a power failure these alarms started to flag up and loss of connections due to the port-channel unbundling.

[balaji.bandi]

If this happening after power Failures only - i will shutdown the port-channel both the sides and bring up see if that fix the issue.

Also check any other Layer 1 issues ?  also make sure  speed nonegotiate (sometime this worked for me when we are connecting different verndors)

Can you also post from cisco and junpier show ethechannel 11 summary

[MHM Cisco World · Accepted solution]

there are cases that make mode of link unpredictable, here cisco side use and support DTP juniper dont support DTP, 
so first time the admin Mode and Op mode is trunk in port member of PortChannel and PortChannel 
after the power failure the admin mode and Op mode is access for port member but it trunk of Portchannel, this happened because Juniper dont support DTP. 
check show interface status
to make this issue not happened again only config port member with 
switchport mode trunk 
i.e. dont use DTP hardcoded the mode to trunk. 

MHM