Symptom

Catalyst 9400 in SVL running 16.12.4 with a non-zero value configured for "stack-mac persistent timer" such as "stack-mac persistent timer 4" will encounter an issue where LACP port-channel members cannot bundle because the LACP Actor ID on the 9400 SVL is not the same, suspending one of the interfaces. The syslog buffer will not report a suspended interface. As an example, there is a suspended interface, the syslog buffer does not record it. Switch#show etherchannel summary Flags: D - down P - bundled in port-channel I - stand-alone s - suspended H - Hot-standby (LACP only) R - Layer3 S - Layer2 U - in use f - failed to allocate aggregator M - not in use, minimum links not met u - unsuitable for bundling w - waiting to be aggregated d - default port A - formed by Auto LAG Number of channel-groups in use: 1 Number of aggregators: 1 Group Port-channel Protocol Ports ------+-------------+-----------+----------------------------------------------- 10 Po10(SU) LACP Gi1/1/0/47(s) Gi2/1/0/47(P) *Dec 10 16:07:30.192: %STACKMGR-6-STANDBY_ELECTED: Chassis 2 R0/0: stack_mgr: Chassis 1 has been elected STANDBY. *Dec 10 16:07:35.125: %REDUNDANCY-5-PEER_MONITOR_EVENT: Active detected a standby insertion (raw-event=PEER_FOUND(4)) *Dec 10 16:07:35.125: %REDUNDANCY-5-PEER_MONITOR_EVENT: Active detected a standby insertion (raw-event=PEER_REDUNDANCY_STATE_CHANGE(5)) *Dec 10 16:07:37.931: %CMRP_PFU-6-PWR_MGMT_OK: Chassis 1 R0/0: cmand: Sufficient number of power supplies (1) are installed for power redundancy mode none (excess power 1685 watts). *Dec 10 16:07:39.809: %TRANSCEIVER-6-INSERTED: Chassis 1 R0/0: iomd: transceiver module inserted in TenGigabitEthernet1/3/0/3 *Dec 10 16:07:41.914: %SPA_OIR-6-ONLINECARD: SPA (C9400-SUP-1XL) online in chassis 1 subslot 3/0 *Dec 10 16:07:46.126: %LINK-3-UPDOWN: Interface TenGigabitEthernet1/3/0/3, changed state to up *Dec 10 16:07:47.126: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/3/0/3, changed state to up *Dec 10 16:08:33.570: %SPA_OIR-6-ONLINECARD: SPA (C9400-LC-48U) online in chassis 1 subslot 5/0 *Dec 10 16:08:36.332: %SPA_OIR-6-ONLINECARD: SPA (C9400-LC-48S) online in chassis 1 subslot 1/0 *Dec 10 16:08:44.837: %TRANSCEIVER-6-INSERTED: Chassis 1 R0/0: iomd: transceiver module inserted in GigabitEthernet1/1/0/47 *Dec 10 16:08:47.451: %LINK-3-UPDOWN: Interface GigabitEthernet1/5/0/1, changed state to up *Dec 10 16:08:48.452: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/5/0/1, changed state to up *Dec 10 16:08:53.610: %LINK-3-UPDOWN: Interface GigabitEthernet1/1/0/47, changed state to up *Dec 10 16:10:16.111: %HA_CONFIG_SYNC-6-BULK_CFGSYNC_SUCCEED: Bulk Sync succeeded *Dec 10 16:10:17.154: %RF-5-RF_TERMINAL_STATE: Terminal state reached for (SSO) *Dec 10 16:13:02.134: %PLATFORM-4-ELEMENT_WARNING: Chassis 2 R0/0: smand: 1/RP/0: limited space - copy files out of flash: directory. flash: value 79% (8635 MB) exceeds warning level 70% (7690 MB). *Dec 10 16:42:49.019: %SYS-6-TTY_EXPIRE_TIMER: (exec timer expired, tty 0 (0.0.0.0)), user Run "show etherchannel summary" to confirm the health of the port-channel and port-channel members.

Conditions

Catalyst 9400 in SVL running 16.12.4 with a non-zero value configured for "stack-mac persistent timer "

Workaround

Do not configure a non-zero value for "stack-mac persistent timer"

Further Problem Description