[c-nsp] Cisco 7600 port-flapping issue

[Peter Persson]

Hi,

I'm having a pretty big issue with a migrationprocess, i will describe how
and why we are doing this.
We are currently migrating from one site to another in a small city, we
want to migrate this as smoothly as possible, so we thought that we could
tag all vlans from the old site, to the new, then move all fibres and then
move the routing.

At the first step we have already run into problems.
When we have moved 700 VLANs the machine gets some error that makes port
Te4/1 to leave the portchannel and down the port shortly (the other side is
still up on linkprotocol)

Vlan 2000-2699 is in total holding 7500 mac-addresses, but its far away
from hw-limit

The port that is flapping, is a routed port and have no traffic.
The uplink where the VLANs is tagged on, looks like this:
 switchport
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 5,99,2000-2699
 switchport mode trunk
 mtu 9216
 spanning-tree bpdufilter enable (Spanning-tree was added as a troubleshoot
option)

We have had this problem on two separate machines (we tried to exclude hw
and sw error)

All logs that appear:
Sep 22 17:29:58.139: %LINEPROTO-5-UPDOWN: Line protocol on Interface
TenGigabitEthernet4/1, changed state to down
Sep 22 17:29:58.155: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Port-channel3, changed state to down
Sep 22 17:29:58.163: %LINK-3-UPDOWN: Interface Port-channel3, changed state
to down
Sep 22 17:29:58.183: %LDP-5-SP: 31.xxx.xxx.xx:0: session hold up initiated
Sep 22 17:29:59.043: %LINEPROTO-5-UPDOWN: Line protocol on Interface
TenGigabitEthernet4/1, changed state to up
Sep 22 17:29:59.047: %LINK-3-UPDOWN: Interface Port-channel3, changed state
to up
Sep 22 17:29:59.051: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Port-channel3, changed state to up
Sep 22 17:29:59.447: %LDP-5-SP: 31.xxx.xxx.xx:0: session recovery succeeded

Old machine is running 7606 with SUP720-3B with 15.2(4)S3a
New machine is running 7606 with SUP720-3BXL with 12.2(33)SRD6 (because of
memory problems we have in 15.2), but we have also tried with identical HW
as the old machine, and got same error.

Have someone of you seen this error before, and maybe got a resolution?

Regards,
Peter