I have a pair of S4048 switches connected together using VLT which each have 2x uplinks to my core S6010 pair (also VLT). The servers connected to the 4048 pair do so with a link to each switch using LACP.
The problem I'm having is that when I reload either one of the 4048 switches it spends 120 seconds rapidly flapping all of the LACP links before actually rebooting. During this time I can also see syslog messages from my core 6010 switches saying they are throttling management traffic due to excessive control messages being received from the 4048 that I've told to reload.
The 4048s are running FTOS 9.10 (0.2) and the 6010s are running FTOS 9.10 (0.1)
A sample of the syslog messages from the 4048s are:
May 30 10:58:11 %STKUNIT1-M:CP %LACP-5-PORT-UNGROUPED: PortChannel-009-Ungrouped: Interface Te 1/9 exited port-channel 9.
May 30 10:58:11 %STKUNIT1-M:CP %IFMGR-5-OSTATE_DN: Changed interface state to down: Po 9
May 30 10:58:11 %STKUNIT1-M:CP %LACP-5-PORT-UNGROUPED: PortChannel-100-Ungrouped: Interface Fo 1/52 exited port-channel 100.
May 30 10:58:11 %STKUNIT1-M:CP %LACP-5-PORT-GROUPED: PortChannel-100-Grouped: Interface Fo 1/52 joined port-channel 100.
May 30 10:58:12 %STKUNIT1-M:CP %IFMGR-5-OSTATE_DN: Changed interface state to down: Po 100
May 30 10:58:12 %STKUNIT1-M:CP %IFMGR-5-OSTATE_UP: Changed interface state to up: Po 100
May 30 10:58:12 %STKUNIT1-M:CP %LACP-5-PORT-GROUPED: PortChannel-100-Grouped: Interface Fo 1/52 joined port-channel 100.
May 30 10:58:13 %STKUNIT1-M:CP %IFMGR-5-OSTATE_UP: Changed interface state to up: Po 100
May 30 10:58:13 %STKUNIT1-M:CP %IFMGR-5-OSTATE_DN: Changed interface state to down: Po 100
May 30 10:58:13 %STKUNIT1-M:CP %LACP-5-PORT-UNGROUPED: PortChannel-100-Ungrouped: Interface Fo 1/52 exited port-channel 100.
May 30 10:58:15 %STKUNIT1-M:CP %IFMGR-5-OSTATE_UP: Changed interface state to up: Po 9
May 30 10:58:15 %STKUNIT1-M:CP %IFMGR-5-OSTATE_DN: Changed interface state to down: Po 9
May 30 10:58:15 %STKUNIT1-M:CP %IFMGR-5-OSTATE_UP: Changed interface state to up: Po 9
May 30 10:58:15 %STKUNIT1-M:CP %IFMGR-5-OSTATE_DN: Changed interface state to down: Po 100
May 30 10:58:15 %STKUNIT1-M:CP %LACP-5-PORT-UNGROUPED: PortChannel-100-Ungrouped: Interface Fo 1/52 exited port-channel 100.
May 30 10:58:15 %STKUNIT1-M:CP %LACP-5-PORT-GROUPED: PortChannel-100-Grouped: Interface Fo 1/52 joined port-channel 100.
May 30 10:58:15 %STKUNIT1-M:CP %IFMGR-5-OSTATE_UP: Changed interface state to up: Po 100
May 30 10:58:16 %STKUNIT1-M:CP %IFMGR-5-OSTATE_DN: Changed interface state to down: Po 100
May 30 10:58:16 %STKUNIT1-M:CP %LACP-5-PORT-UNGROUPED: PortChannel-100-Ungrouped: Interface Fo 1/52 exited port-channel 100.
May 30 10:58:16 %STKUNIT1-M:CP %IFMGR-5-OSTATE_DN: Changed interface state to down: Po 9
May 30 10:58:17 %STKUNIT1-M:CP %IFMGR-5-OSTATE_UP: Changed interface state to up: Po 9
The config from interface Te 1/9 is:
interface TenGigabitEthernet 1/9
no ip address
mtu 9216
port-channel-protocol LACP
port-channel 9 mode active
no shutdown
....and the config from the port channel is:
interface Port-channel 9
no description
no ip address
mtu 9216
portmode hybrid
switchport
spanning-tree rstp edge-port bpduguard shutdown-on-violation
lacp fast-switchover
vlt-peer-lag port-channel 9
no shutdown
I'd appreciate any insight anyone can give on this.
Thanks.