We have a 3900 series G2 running 15.0(1)M4. It seems there are alot of differences with the 15.0 code. I was intrigued by the ability to do a port-channel on the router instead of having to use something like HSRP or GLBP for HA. The router is going to be a sip gateway only so I wanted to give it dual links to our core switches for extra protection. I configured the device in the following way and to my surprise it works fine. Whats scary is I would think this would cause a loop because I did not have a port-channel configured on the other side and on the router if I do a show etherchanel summary nothing is present. Any ideas?
show run | beg interface
!
interface Port-channel1
ip address 10.1.210.15 255.255.255.0
hold-queue 150 in
!
interface GigabitEthernet0/0
no ip address
duplex auto
speed auto
!
interface GigabitEthernet0/1
no ip address
duplex auto
speed auto
channel-group 1
!
interface GigabitEthernet0/2
no ip address
duplex auto
speed auto
channel-group 1
!
show etherchannel summary
Flags: D - down P - in port-channel
I - stand-alone s - suspended
R - Layer3 S - Layer2
U - in use
Group Port-channel Ports
-----+------------+-----------------------------------------------------------
CORP_SIP_01#
CORP_SIP_01#show ip int brief
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0 unassigned YES manual down down
GigabitEthernet0/1 unassigned YES NVRAM up up
GigabitEthernet0/2 unassigned YES NVRAM up up
Loopback0 unassigned YES unset up up
Port-channel1 10.1.210.15 YES manual up up
You should really look at things at the switch side.
Found this article which was helpful. Still doesn't explain why the etherchannel doesn't show up in the router when I do a show etherchannel summary.
http://www.cisco.com/en/US/tech/tk389/tk213/technologies_configuration_example09186a0080094958.shtml