02-28-2014 07:39 AM
We have the situation, that an existing and working 2x1GE LACP vLAG Portchannel between our VDX6710 Fabric and a Cisco ASR1002-X outer stops working when one of the VDX will be rebooted. After such a VDX reboot the flapped interface of the Portchannel stays in the "hot-standby" status.
The LACP status of the flapped interface on the ASR went from "bundled" (vLAG Portchannel works) over "down" (VDX offline/reboot) to "hot-standby" (VDX is back online). Even a shut/no-shut on every interface on both systems does not bring the status back to "bundled", it toggles between "down" and "hot-standby".
We have changed some LACP parameters (e.g. active/passive directions, active/active setup and system priorities) without any success and the interface chracteristics (speed/duplex, priority, max-/min bundled interfaces, fast/slow timers) are the same on VDX and ASR.
Have somebody observed any similar behavior? The Firmware is NOS4.1.0 on VDX and IOS-XE3.11.0S on the ASR.
For now we have configured an static vLAG Portchannel (no LACP / "on") as a workaround. This method seems to work as expected but we would prefer the dynamic LACP style.