High Availability

Feature History for High Availability

This table provides release and related information for the features explained in this module.

These features are available in all the releases subsequent to the one they were introduced in, unless noted otherwise.

Table 1. Feature History for High Availability

Release

Feature

Feature Information

Cisco IOS XE 17.18.1

Enhanced Gateway Reachability Statistics

Improves visibility into gateway reachability and provides detailed statistics for ICMP, ARP, and ND probes. This feature enables simplified troubleshooting, greater transparency, and more reliable diagnostics for HA and RMI functionality.

The following command is introduced:

  • show platform software rif-mgr chassis { active | standby} r0 gateway-statistics

The following command is modified:

  • show platform software rif-mgr chassis { active | standby} r0 resource-status

Cisco IOS XE Amsterdam 17.1.1s

Redundant Management Interface

The Redundancy Management Interface (RMI) is used as a secondary link between the active and standby controllers. This interface is the same as the Wireless Management Interface and the IP address on this interface is configured in the same subnet as the Wireless Management Interface.

Information About High Availability

High Availability (HA) allows you to reduce the downtime of wireless networks that occurs due to the failover of controllers. The HA Stateful Switch Over (SSO) capability on the controller allows AP to establish a CAPWAP tunnel with the active controller. The active controller shares a mirror copy of the AP and client database with the standby controller. The APs won’t go into the discovery state and clients don’t disconnect when the active controller fails. The standby controller takes over the network as the active controller. Only one CAPWAP tunnel is maintained between the APs and the controller that is in an active state.

HA supports full AP and client SSO. Client SSO is supported only for clients that have completed the authentication and DHCP phase, and have started passing traffic. With Client SSO, the client information is synced to the standby controller when the client associates to the controller or when the client parameters change. Fully authenticated clients, for example, the ones in RUN state, are synced to the standby. Thus, client reassociation is avoided on switchover making the failover seamless for the APs and clients, resulting in zero client service downtime and zero SSID outage. This feature reduces major downtime in wireless networks due to failure conditions such as box failover, network failover, or power outage on the primary site.


Note

Note

When the controller works as a host for spanning tree, ensure that you configure portfast trunk, using spanning-tree port type edge trunk or spanning-tree portfast trunk commands, in the uplink switch to ensure faster convergence.


Note

You can configure FIPS in HA setup. For information, see the Configuring FIPS in HA Setup.


Note

The IPv4 secondary address is used internally for RMI purpose. So, it is not recommended to configure the secondary IPv4 address.

In case of IPv6, only one management IPv6 is allowed, secondary address is configured for RMI-IPv6 purpose. It is not recommended to have more than one IPv6 management on the Wireless Management Interface (WMI).

More than one management IPv4 and IPv6 addresses on WMI can result in unpredictable behavior.

Prerequisites for High Availability

External Interfaces and IPs

Because all the interfaces are configured only on the Active box, but are synchronized with the Standby box, the same set of interfaces are configured on both controllers. From external nodes, the interfaces connect to the same IP addresses, irrespective of the controllers they are connected to.

For this purpose, the APs, clients, DHCP, Cisco Prime Infrastructure, Cisco Catalyst Centre, and Cisco Identity Services Engine (ISE) servers, and other controller members in the mobility group always connect to the same IP address. The SSO switchover is transparent to them. But if there are TCP connections from external nodes to the controller, the TCP connections need to be reset and reestablished.

HA Interfaces

The HA interface serves the following purposes:

  • Provides connectivity between the controller pair before an IOSd comes up.

  • Provides IPC transport across the controller pair.

  • Enables redundancy across control messages exchanged between the controller pair. The control messages can be HA role resolution, keepalives, notifications, HA statistics, and so on.

You can select either SFP or RJ-45 connection for HA port. Supported Cisco SFPs are:

  • GLC-SX-MMD

  • GLC-LH-SMD

When either SFP or RJ-45 connection is present, HA works between the two controllers. The SFP HA connectivity takes priority over RJ-45 HA connectivity. If SFP is connected when RJ-45 HA is up and running, the HA pair reloads. The reload occurs even if the link between the SFPs isn’t connected.

When either SFP or RJ-45 connection is present, HA works between the two controllers. If SFP is connected when RJ-45 HA is up and running, the HA pair reloads. The reload occurs even if the link between the SFPs isn’t connected.


Note

Connect RPs via switches to enable controller HA. Ensure that the round-trip time between the two controllers is less than 80 milliseconds.

Restrictions on High Availability

  • For a fail-safe SSO, wait till you receive the switchover event after completing configuration synchronization on the standby controller. If the standby controller has just been booted up, we recommend that you wait x minutes before the controller can handle switchover events without any problem. The value of x can change based on the platform. For example, a Cisco 9800-80 Series Controller running to its maximum capacity can take up to 24 minutes to complete the configuration synchronization before being ready for SSO. You can use the show wireless stats redundancy config database command to view the database-related statistics.

  • The flow states of the NBAR engine are lost during a switchover in an HA scenario in local mode. Because of this, the classification of flows will restart, leading to incorrect packet classification as the first packet of the flow is missed.

  • The HA connection supports only IPv4.

  • Switchover and an active reload and forces a high availability link down from the new primary.

  • Standby RMI interface does not support Web UI access.

  • Two HA interfaces (RMI and RP) must be configured on the same subnet, and the subnet cannot be shared with any other interfaces on the device.

  • It is not possible to synchronize a TCP session state because a TCP session cannot survive after a switchover, and needs to be reestablished.

  • The Client SSO does not address clients that have not reached the RUN state because they are removed after a switchover.

  • Statistics tables are not synced from active to standby controller.

  • Machine snapshot of a VM hosting controller HA interfaces is not supported. It may lead to a crash in the HA controller.

  • Mobility-side restriction: Clients which are not in RUN state will be forcefully reauthenticated after switchover.

  • The following application classification may not be retained after the SSO:

    • AVC limitation—After a switchover, the context transfer or synchronization to the Standby box does not occur and the new active flow needs to be relearned. The AVC QoS does not take effect during classification failure.

    • A voice call cannot be recognized after a switchover because a voice policy is based on RTP or RTCP protocol.

    • Auto QoS is not effective because of AVC limitation.

  • The active controller and the standby controller must be paired with the same interface for virtual platforms. For hardware appliance, there is a dedicated HA port.

  • Static IP addressing can synch to standby, but the IP address cannot be used from the standby controller.

  • You can map a dedicated HA port to a 1 GB interface only.

  • To use EtherChannels in HA mode in releases until, and including, Cisco IOS XE Gibraltar 16.12.x, ensure that the channel mode is set to On.

  • EtherChannel Auto-mode is not supported in HA mode in releases until, and including, Cisco IOS XE Gibraltar 16.12.x.

  • LACP and PAGP is not supported in HA mode in releases until, and including, Cisco IOS XE Gibraltar 16.12.x.

  • When the controller works as a host for spanning tree, ensure that you configure portfast trunk in the uplink switch using spanning-tree port type edge trunk or spanning-tree portfast trunk command to ensure faster convergence.

  • The clear chassis redundancy and write erase commands will not reset the chassis priority to the default value.

  • While configuring devices in HA, the members must not have wireless trustpoint with the same name and different keys. In such a scenario, if you form an HA pair between the two standalone controllers, the wireless trustpoint does not come up after a subsequent SSO. The reason being the rsa keypair file exists but it is incorrect as the nvram:private-config file is not synched with the actual WLC_WLC_TP key pair.

    As a best practice, before forming an HA, it is recommended to delete the existing certificates and keys in each of the controllers which were previously deployed as standalone.

  • After a switchover, when the recovery is in progress, do not configure the WLAN or WLAN policy. In case you configure, the controller can crash.

  • After a switchover, clients that are not in RUN state and not connected to an AP are deleted after 300 seconds.

Guidelines for RP Port Configuration

The following are guidelines for RP port configuration:

  • The IP addresses for Local and Remote IP must be in the same subnet.

  • Use the 169.254.X.X/16 subnet; derive the last two octets from the management interface.

  • Avoid using 10.10.10.x/24 subnet for the RP port.

  • For more information about RMI+RP chosen as the redundancy method, see Information About Redundancy Management Interface.

Configuring High Availability (CLI)

Before you begin

The active and standby controller should be in the same mode, either Install mode or Bundle mode, with same image version. We recommend that you use Install mode.

Procedure

  Command or Action Purpose

Step 1

chassis chassis-num priority chassis-priority

Example:

Device# chassis 1 priority 1

(Optional) Configures the priority of the specified device.

Note

 

From Cisco IOS XE Gibraltar 16.12.x onwards, device reload is not required for the chassis priority to become effective.

  • chassis-num —Enter the chassis number. The range is from 1 to 2.

  • chassis-priority —Enter the chassis priority. The range is from 1 to 2. The default value is 1.

Note

 

When both the devices boot up at the same time, the device with higher priority(2) becomes active, and the other one becomes standby. If both the devices are configured with the same priority value, the one with the smaller MAC address acts as active and its peer acts as standby.

Step 2

chassis redundancy ha-interface GigabitEthernet numlocal-ip local-chassis-ip-addr network-mask remote-ip remote-chassis-ip-addr

Example:

Device# chassis redundancy ha-interface 
GigabitEthernet 2 local-ip 4.4.4.1 /24 remote-ip 4.4.4.2

Configures the chassis high availability parameters.

  • num —GigabitEthernet interface number. The range is from 0 to 32.

  • local-chassis-ip-addr —Enter the IP address of the local chassis HA interface.

  • network-mask —Enter the network mask or prefix length in the /nn or A.B.C.D format.

  • remote-chassis-ip-addr —Enter the remote chassis IP address.

Step 3

chassis redundancy keep-alive timer timer

Example:

Device# chassis redundancy keep-alive timer 6

Configures the peer keepalive timeout value.

Time interval is set in multiple of 100 ms (enter 1 for default).

Step 4

chassis redundancy keep-alive retries retry-value

Example:

Device# chassis redundancy keep-alive retries 8

Configures the peer keepalive retry value before claiming peer is down. Default value is 5.

Disabling High Availability

If the controller is configured using RP method of SSO configuration, use the following command to clear all the HA-related parameters, such as local IP, remote IP, HA interface, mask, timeout, and priority:

clear chassis redundancy


Note

This command is not supported on these models:

  • Cisco Catalyst CW9800H1 Wireless Controller.

  • Cisco Catalyst CW9800H2 Wireless Controller.

  • Cisco Catalyst CW9800M Wireless Controller.

    RMI-based High Availability is mandatory in the Cisco Catalyst CW9800H1 Wireless Controller, Cisco Catalyst CW9800H2 Wireless Controller and Cisco Catalyst CW9800M Wireless Controller.

If the controller is configured using RMI method, use the following command:

no redun-management interface vlan chassis


Note

Reload the devices for the changes to take effect.

After the HA unpairing, the standby controller startup configuration and the HA configuration will be cleared and standby will go to Day 0.

Before the command is executed, the user is prompted with the following warning on the active controller:


Device# clear chassis redundancy

WARNING: Clearing the chassis HA configuration will result in both the chassis move into
Stand Alone mode. This involves reloading the standby chassis after clearing its HA
configuration and startup configuration which results in standby chassis coming up as a totally
clean after reboot. Do you wish to continue? [y/n]? [yes]:

*Apr 3 23:42:22.985: received clear chassis.. ha_supported:1yes
WLC#
*Apr 3 23:42:25.042: clearing peer startup config
*Apr 3 23:42:25.042: chkpt send: sent msg type 2 to peer..
*Apr 3 23:42:25.043: chkpt send: sent msg type 1 to peer..
*Apr 3 23:42:25.043: Clearing HA configurations
*Apr 3 23:42:26.183: Successfully sent Set chassis mode msg for chassis 1.chasfs file updated
*Apr 3 23:42:26.359: %IOSXE_REDUNDANCY-6-PEER_LOST: Active detected chassis 2 is no
longer standby

On the standby controller, the following messages indicate that the configuration is being cleared:

Device-stby#

*Apr 3 23:40:40.537: mcprp_handle_spa_oir_tsm_event: subslot 0/0 event=2
*Apr 3 23:40:40.537: spa_oir_tsm subslot 0/0 TSM: during state ready, got event 3(ready)
*Apr 3 23:40:40.537: @@@ spa_oir_tsm subslot 0/0 TSM: ready -> ready
*Apr 3 23:42:25.041: Removing the startup config file on standby

!Standby controller is reloaded after clearing the chassis.

Verifying High Availability Configurations

To view the HA configuration details, use the following command:

Device# show romvar
ROMMON variables:
 LICENSE_BOOT_LEVEL =
 MCP_STARTUP_TRACEFLAGS = 00000000:00000000
 BOOTLDR =
 CRASHINFO = bootflash:crashinfo_RP_00_00_20180202-034353-UTC
 STACK_1_1 = 0_0
 CONFIG_FILE =
 BOOT = bootflash:boot_image_test,1;bootflash:boot_image_good,1;bootflash:rp_super_universalk9.vwlc.bin,1;
 RET_2_RTS =
 SWITCH_NUMBER = 1
 CHASSIS_HA_REMOTE_IP = 10.0.1.9
 CHASSIS_HA_LOCAL_IP = 10.0.1.10
 CHASSIS_HA_LOCAL_MASK = 255.255.255.0
 CHASSIS_HA_IFNAME = GigabitEthernet2
 CHASSIS_HA_IFMAC = 00:0C:29:C9:12:0B
 RET_2_RCALTS =
 BSI = 0
 RANDOM_NUM = 647419395

Verifying AP or Client SSO Statistics

To view the AP SSO statistics, use the following command:

Device# show wireless stat redundancy statistics ap-recovery wnc all
AP SSO Statistics                                                     

Inst    Timestamp     Dura(ms)   #APs  #Succ  #Fail  Avg(ms)  Min(ms)  Max(ms)
------------------------------------------------------------------------------
   0    00:06:29.042        98     34     34      0        2        1       35
   1    00:06:29.057        56     33     30      3        1        1       15
   2    00:06:29.070        82     33     33      0        2        1       13


Statistics:

WNCD Instance   : 0
No. of AP radio recovery failures          : 0
No. of AP BSSID recovery failures          : 0
No. of CAPWAP recovery failures            : 0
No. of DTLS recovery failures              : 0
No. of reconcile message send failed       : 0
No. of reconcile message successfully sent : 34
No. of Mesh BSSID recovery failures: 0
No. of Partial delete cleanup done : 0
.
.
.

To view the Client SSO statistics, use the following command:

Device# show wireless stat redundancy client-recovery wncd all
Client SSO statistics                                                      
----------------------                                                     

WNCD instance  : 1
Reconcile messages received from AP                     : 1
Reconcile clients received from AP                      : 1
Recreate attempted post switchover                      : 1
Recreate attempted by SANET Lib                         : 0
Recreate attempted by DOT1x Lib                         : 0
Recreate attempted by SISF Lib                          : 0
Recreate attempted by SVC CO Lib                        : 1
Recreate attempted by Unknown Lib                       : 0
Recreate succeeded post switchover                      : 1
Recreate Failed post switchover                         : 0
Stale client entries purged post switchover             : 0

Partial delete during heap recreate                     : 0
Partial delete during force purge                       : 0
Partial delete post restart                             : 0
Partial delete due to AP recovery failure               : 0
Partial delete during reconcilation                     : 0

Client entries in shadow list during SSO                : 0
Client entries in shadow default state during SSO       : 0
Client entries in poison list during SSO                : 0

Invalid bssid during heap recreate                      : 0
Invalid bssid during force purge                        : 0
BSSID mismatch with shadow rec during reconcilation     : 0
BSSID mismatch with shadow rec reconcilation(WGB client): 0
BSSID mismatch with dot11 rec during heap recreate      : 0

AID mismatch with dot11 rec during force purge          : 0
AP slotid mismatch during reconcilation                 : 0
Zero aid during heap recreate                           : 0
AID mismatch with shadow rec during reconcilation       : 0
AP slotid mismatch shadow rec during reconcilation      : 0
Client shadow record not present                        : 0

To view the mobility details, use the following command:

Device# show wireless stat redundancy client-recovery mobilityd
Mobility Client Deletion Reason Statistics
-------------------------------------------
Mobility Incomplete State         : 0
Inconsistency in WNCD & Mobility  : 0
Partial Delete                    : 0

General statistics
--------------------
Cleanup sent to WNCD, Missing Delete case   : 0

To view the Client SSO statistics for SISF, use the following command:

Device# show wireless stat redundancy client-recovery sisf
Client SSO statistics for SISF
--------------------------------
Number of recreate attempted post switchover    : 1
Number of recreate succeeded post switchover    : 1
Number of recreate failed because of no mac     : 0
Number of recreate failed because of no ip      : 0
Number of ipv4 entry recreate success           : 1
Number of ipv4 entry recreate failed            : 0
Number of ipv6 entry recreate success           : 0
Number of ipv6 entry recreate failed            : 0
Number of partial delete received               : 0
Number of client purge attempted                : 0
Number of heap and db entry purge success       : 0
Number of purge success for db entry only       : 0
Number of client purge failed                   : 0
Number of garp sent                             : 1
Number of garp failed                           : 0
Number of IP entries validated in cleanup       : 0
Number of IP entry address errors in cleanup    : 0
Number of IP entry deleted in cleanup           : 0
Number of IP entry delete failed in cleanup     : 0
Number of IP table create callbacks on standby  : 0
Number of IP table modify callbacks on standby  : 0
Number of IP table delete callbacks on standby  : 0
Number of MAC table create callbacks on standby : 1
Number of MAC table modify callbacks on standby : 0
Number of MAC table delete callbacks on standby : 0

To view the HA redundancy summary, use the following command:

Device# show wireless stat redundancy summary
HA redundancy summary
---------------------

AP recovery duration (ms)        : 264
SSO HA sync timer expired        : No

Verifying High Availability

Table 2. Commands for Monitoring Chassis and Redundancy
Command Name Description
show chassis

Displays the chassis information.

Note

 

When the peer timeout and retries are configured, the show chassis ha-status command output may show incorrect values.

To check the peer keep-alive timer and retries, use the following commands:

  • show platform software stack-mgr chassis active r0 peer-timeout

  • show platform software stack-mgr chassis standby r0 peer-timeout

show redundancy

Displays details about Active box and Standby box.

show redundancy switchover history

Displays the switchover counts, switchover reason, and the switchover time.

To start the packet capture in the redundancy HA port (RP), use the following commands:

  • test wireless redundancy packet dump start

  • test wireless redundancy packet dump stop

  • test wireless redundancy packet dump start filter port 2300

Device# test wireless redundancy packetdump start
Redundancy Port PacketDump Start
Packet capture started on RP port.

Device# test wireless redundancy packetdump stop
Redundancy Port PacketDump Start
Packet capture started on RP port.
Redundancy Port PacketDump Stop
Packet capture stopped on RP port.
Device# dir bootflash:                           
Directory of bootflash:/
1062881  drwx           151552  Oct 20 2020 23:15:25 +00:00  tracelogs
47      -rw-            20480  Oct 20 2020 23:15:24 +00:00  haIntCaptureLo.pcap
1177345  drwx             4096  Oct 20 2020 19:56:14 +00:00  certs
294337  drwx             8192  Oct 20 2020 19:56:05 +00:00  license_evlog
15      -rw-              676  Oct 20 2020 19:56:01 +00:00  vlan.dat
14      -rw-               30  Oct 20 2020 19:55:16 +00:00  throughput_monitor_params
13      -rw-           134808  Oct 20 2020 19:54:57 +00:00  memleak.tcl
1586145  drwx             4096  Oct 20 2020 19:54:45 +00:00  .inv
1103761  drwx             4096  Oct 20 2020 19:54:39 +00:00  dc_profile_dir
17      -r--              114  Oct 20 2020 19:54:17 +00:00  debug.conf
1389921  drwx             4096  Oct 20 2020 19:54:17 +00:00  .installer
46      -rw-       1104760207  Oct 20 2020 19:26:41 +00:00  leela_katar_rping_test.SSA.bin
49057   drwx             4096  Oct 20 2020 16:11:21 +00:00  .prst_sync
45      -rw-       1104803200  Oct 20 2020 15:39:19 +00:00  C9800-L-universalk9_wlc.2020-10-20_14.57_yavadhan.SSA.bin
269809  drwx             4096  Oct 19 2020 23:41:49 +00:00  core
44      -rw-       1104751981  Oct 19 2020 17:42:12 +00:00  C9800-L-universalk9_wlc.BLD_POLARIS_DEV_LATEST_20201018_053825_2.SSA.bin
43      -rw-       1104286975  Oct 16 2020 12:05:47 +00:00  C9800-L-universalk9_wlc.BLD_POLARIS_DEV_LATEST_20201010_001654_2.SSA.bin

Device# test wireless redundancy packetdump start filter port 2300
Redundancy Port PacketDump Start
Packet capture started on RP port with port filter 2300.

To check connection between the two HA Ports (RP) and check if there are any drops, delays, or jitter in the connection, use the following command: 

Device# test wireless redundancy rping
Redundancy Port ping
PING 169.254.64.60 (169.254.64.60) 56(84) bytes of data.
64 bytes from 169.254.64.60: icmp_seq=1 ttl=64 time=0.083 ms
64 bytes from 169.254.64.60: icmp_seq=2 ttl=64 time=0.091 ms
64 bytes from 169.254.64.60: icmp_seq=3 ttl=64 time=0.074 ms

--- 169.254.64.60 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2041ms
rtt min/avg/max/mdev = 0.074/0.082/0.091/0.007 ms
test wireless redundancy

To see the HA port interface setting status, use the show platform hardware slot R0 ha_port interface stats command. 


Device# show platform hardware slot R0 ha_port interface stats
HA Port
ha_port   Link encap:Ethernet  HWaddr 70:18:a7:c8:80:70
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Memory:e0900000-e0920000

Settings for ha_port:
        Supported ports:            [ TP ]
        Supported link modes:       10baseT/Half 10baseT/Full
                                    100baseT/Half 100baseT/Full
                                    1000baseT/Full
        Supported pause frame use:   Symmetric
        Supports auto-negotiation:   Yes
        Supported FEC modes:         Not reported
        Advertised link modes:       10baseT/Half 10baseT/Full
                                     100baseT/Half 100baseT/Full
                                     1000baseT/Full
        Advertised pause frame use:  Symmetric
        Advertised auto-negotiation: Yes
        Advertised FEC modes:        Not reported
        Speed:                       Unknown!
        Duplex:                      Unknown! (255)
        Port:                        Twisted Pair
        PHYAD:                       1
        Transceiver:                 internal
        Auto-negotiation:            on
        MDI-X:                       off (auto)
        Supports Wake-on:            pumbg
        Wake-on:                     g
        Current message level:       0x00000007 (7)
                                     drv probe link
        Link detected:               no

NIC statistics:
     rx_packets:             0
     tx_packets:             0
     rx_bytes:               0
     tx_bytes:               0
     rx_broadcast:           0
     tx_broadcast:           0
     rx_multicast:           0
     tx_multicast:           0
     multicast:              0
     collisions:             0
     rx_crc_errors:          0
     rx_no_buffer_count:     0
     rx_missed_errors:       0
     tx_aborted_errors:      0
     tx_carrier_errors:      0
     tx_window_errors:       0
     tx_abort_late_coll:     0
     tx_deferred_ok:         0
     tx_single_coll_ok:      0
     tx_multi_coll_ok:       0
     tx_timeout_count:       0
     rx_long_length_errors:  0
     rx_short_length_errors: 0
     rx_align_errors:        0
     tx_tcp_seg_good:        0
     tx_tcp_seg_failed:      0
     rx_flow_control_xon:    0
     rx_flow_control_xoff:   0
     tx_flow_control_xon:    0
     tx_flow_control_xoff:   0
     rx_long_byte_count:     0
     tx_dma_out_of_sync:     0
     tx_smbus:               0   
     rx_smbus:               0
     dropped_smbus:          0
     os2bmc_rx_by_bmc:       0
     os2bmc_tx_by_bmc:       0
     os2bmc_tx_by_host:      0
     os2bmc_rx_by_host:      0
     tx_hwtstamp_timeouts:   0
     rx_hwtstamp_cleared:    0
     rx_errors:              0
     tx_errors:              0
     tx_dropped:             0
     rx_length_errors:       0
     rx_over_errors:         0
     rx_frame_errors:        0
     rx_fifo_errors:         0
     tx_fifo_errors:         0
     tx_heartbeat_errors:    0
     tx_queue_0_packets:     0
     tx_queue_0_bytes:       0
     tx_queue_0_restart:     0
     tx_queue_1_packets:     0
     tx_queue_1_bytes:       0
     tx_queue_1_restart:     0
     rx_queue_0_packets:     0
     rx_queue_0_bytes:       0
     rx_queue_0_drops:       0
     rx_queue_0_csum_err:    0
     rx_queue_0_alloc_failed:0
     rx_queue_1_packets:     0
     rx_queue_1_bytes:       0
     rx_queue_1_drops:       0
     rx_queue_1_csum_err:    0
     rx_queue_1_alloc_failed:0

Configuring a Switchover

Procedure

Command or Action Purpose

To force a failover to the standby unit, use the following command:

Example:

Device#redundancy force-switchover

In this case, the standby controller will take the role of the active controller, and the active controller will reload and become the new standby controller. This command can be used to test the stability of the high availability cluster and see if switchovers are working as expected.

Note

 

Do not use any other command to test switchovers between the Cisco Catalyst 9800 series wireless controllers. Command such as "reload slot X" (where X is the active controller) might lead to unexpected behaviour and should not be used to perform a switchover.

Note

 

In a scaled environment, it is recommended to not perform an immediate switchover after the WLAN or policy profile configurations are modified as it might lead to unexpected behaviour.

Redundancy Management Interfaces

The Redundancy Management Interface (RMI) is a key feature for high availability (HA) in Cisco Catalyst 9800 Series Wireless Controllers. This chapter presents foundational concepts, processes, reference tables, configuration tasks, and principles related to RMI, its pairing scenarios, gateway monitoring, and troubleshooting. It covers information for both IPv4 and IPv6 dual stack support, dynamic pairing, upgrade/downgrade behaviors, and the configuration of gateway monitoring, as well as practical recommendations for ARP handling and AAA integration.

Redundancy management interfaces

A redundancy management interface is a network interface that

  • acts as a secondary link between active and standby wireless controllers,

  • enables resource health information exchange (such as gateway reachability), and

  • assists in the detection of dual-active controller conditions to maintain high availability.

The RMI might trigger a switchover based on the gateway status on the controllers.

Subdefinitions:

  • Active controller: Uses the management IP as the primary address and RMI as the secondary IPv4 address on the management VLAN. RMI configuration is automatic.

    Analogy: Like a city’s current mayor who’s in charge, but always ready to hand over leadership if needed.

  • Standby controller: Has the RMI IP as the primary address; upon switchover, roles and addresses are swapped.

    Analogy: Like a vice-mayor who takes the mayor’s seat (with all responsibilities and keys) when the mayor is away.

  • RP (Redundancy Port): The main dedicated physical link for state and configuration synchronization between active and standby controllers; loss of both RP and RMI links results in high availability (HA) failures.

    (Analogy: Like the main road connecting two city offices, critical for daily business and coordination).

  • WMI (Wireless Management Interface): The main management interface for controller operations and communications; shares its subnet with the RMI and may serve as a source address for certain types of traffic such as AAA packets.

    Analogy: Like a city’s public headquarters, used for both regular operations and official correspondence.

  • RMI (Redundancy Management Interface): A dedicated network interface that serves as a secondary communication path between controllers for exchanging resource health information, detecting dual-active conditions, and monitoring gateway reachability; shares the same subnet as the Wireless Management Interface (WMI).

    Analogy: Like an emergency side road connecting two city halls, used for urgent official communication.

  • HA (High Availability): A deployment setup where controllers operate as an active-standby pair to ensure uninterrupted wireless services; relies on RP and RMI links for failover and role management.

  • ARP table: A database on a network device such as a switch that maintains mappings between IP addresses and MAC addresses; determines how to forward traffic within the local network.

    (Analogy: Like a city map book held by delivery drivers in neighboring towns, showing them which mayor is at which city hall, so the right deliveries go to the right address.)

  • GARP (Gratuitous ARP): A type of ARP (Address Resolution Protocol) packet broadcast by a controller, typically after a switchover, to update the ARP tables in connected network switches with the correct IP-to-MAC address mappings.

    (Analogy: Like sending out an urgent memo to all nearby towns, telling them who the new mayor is so they update their city maps immediately after a leadership change.)

  • ARP cache timeout: The duration for which an entry in the ARP table is considered valid before it must be refreshed; reducing this value helps the network recover quickly after role or address changes in the controllers.

    (Analogy: Like setting a regular schedule for when all delivery drivers check for updates to the city map books, ensuring they quickly recognize changes in city leadership or addresses.)

  • SGACL (Security Group Access Control List): A policy configuration that determines which types of network traffic (e.g., ICMP, ARP) are permitted between specific interfaces or devices, such as the RMI addresses of controllers.

    (Analogy: Like special city rules that decide which types of emergency vehicles are allowed to travel the emergency road between city halls.)

  • ICMP (Internet Control Message Protocol): A network protocol used for sending error messages and operational information between network devices; essential for controllers to monitor each other’s status over the RMI.

    (Analogy: Like sending quick bike couriers to report on the status of the roads or to alert if there’s trouble between cities.)

  • AAA (Authentication, Authorization, and Accounting): A framework for controlling user access to network resources and tracking user activity; controllers may send AAA-related packets from either the WMI IP or the RMI IP, so the AAA server must recognize both as valid.

    (Analogy: Like having a security checkpoint that logs who enters or exits city buildings, whether they come from Main Street (WMI) or the emergency road (RMI).)

  • SGT (Security Group Tag): An identification label assigned to network devices for policy enforcement with Cisco TrustSec; mapping is applied for both RMI and WMI addresses when device SGTs are used.

    Analogy: Like giving every city vehicle a badge, so officials can enforce special rules for each group whether they use Main Street or the emergency road.

  • Cisco TrustSec: A security architecture that uses SGTs to enforce network segmentation and access control policies; not supported on the RMI interface.

    Analogy: Like a city’s security zone system—effective on main city roads, but not supported on the emergency side road.

Limitations for RMI

  • Cisco TrustSec is not supported on the RMI.

Best practices for RMI

  • Ensure that the SGACL is defined appropriately to allow ICMP and ARP traffic between the active and standby RMI addresses when device SGT is used, since the IP-SGT mapping applies to both the RMI and WMI addresses.

Important: gateway monitoring interval and detection time

  • When gateway reachability is enabled, both the active and standby controllers check gateway status through the RMI interface.

  • It takes approximately the configured gateway monitoring interval to detect when a controller has lost gateway reachability.

  • The default gateway monitoring interval is eight seconds, so the minimum detection time is about eight seconds unless you configure a different value.

Analogy

Think of redundancy management interfaces (RMI) as an emergency backup road that connects two cities (the active and standby controllers). The main highway (the redundancy port, RP) handles most of the day-to-day traffic and coordination. If the main highway is blocked or damaged, the emergency road (RMI) ensures that vital information—such as each city's health, status, and road conditions—can still be exchanged quickly.

Just as emergency vehicles and communication must be allowed to travel the backup road (analogous to allowing ICMP and ARP traffic via SGACL), the RMI helps both cities detect if both try to take charge at the same time (dual-active condition) and exchange important information about the area's main gateway (gateway status). If both the highway and the emergency road are inaccessible, each city might assume it’s in charge, resulting in confusion (an IP conflict). The ARP table is like city maps in other towns (switches) that may not immediately recognize which city is currently in charge after both reconnect—setting these maps to update frequently (low ARP cache timeout) allows for faster recovery from major outages.

Active or Standby Controller Operations with RMI

The active controller assigns IP addresses as follows:

  • The primary address is the management IP address.

  • The secondary IPv4 address on the management VLAN is the RMI (Redundant Management Interface) IP address for the active controller.

The standby controller manages IP addresses in a high-availability setup as follows:

  • It does not have the wireless management IP configured.

  • The RMI IP address is configured as the primary IP address on the standby controller.

  • When the standby controller becomes active, the management IP address becomes the primary IP address, and the RMI IP address becomes the secondary IP address.

  • If the interface on the active controller is administratively down, the same state is reflected on the standby controller


Note

Do not configure the secondary IPv4 address explicitly. RMI automatically configures a single secondary IPv4 address under the RMI.

Dual stack support on management VLAN with RMI

A dual stack configuration is a network interface setup that

  • allows both IPv4 and IPv6 addresses to be configured on the wireless management interface,

  • permits monitoring only of the gateway that matches the configured RMI address family (IPv4 or IPv6), and

  • restricts the visibility of the alternate family’s management address on the standby controller.

Expanded Explanation

  • Dual stack refers to the fact that the wireless management interface can be configured with IPv4 and IPv6 addresses. If an RMI IPv4 address is configured along with an IPv4 management IP address, you can additionally configure an IPv6 management address on the wireless management interface. This IPv6 management IP address will not be visible on the standby controller.


Note

The RMI feature supports only RMI IPv4 addresses.

RMI-Based High-Availability Pairings

A RMI-based high-availability pair is a controller deployment configuration that:

  • uses Remote Machine Interface (RMI) to synchronize two controllers,

  • provides redundancy by designating active and standby roles, and

  • ensures failover and persistent state during controller reloads or outages.

RMI-Based High-Availability Pairing Scenarios and Device Support

You should consider RMI-based high-availability pairs in the following scenarios:

  • Fresh installation: Configure high availability during the initial setup of controllers.

  • Already paired controllers: Adjust or reconfigure pairing for controllers that are already part of a high-availability pair.

  • Upgrade scenario: Maintain or update the pair relationship during software or hardware upgrades.

  • Downgrade scenario: Ensure pairing remains stable and functional during downgrades.

Dynamic high-availability (HA) pairing requires both the active and standby controllers to reload. In practice, on the Cisco Catalyst 9800-L, 9800-40, and 9800-80 Wireless Controllers, dynamic pairing occurs when one controller reloads and becomes the standby member of the pair.


Note

Unique chassis numbers must be configured for each controller before forming an HA pair, as these numbers identify the controllers within the pair.

HA Pairing Without Previous Configuration

A high-availability (HA) pairing without previous configuration is a deployment scenario for wireless controllers that:

  • initiates the HA setup on devices without existing ROMMON variables for RP (Route Processor) IP addresses,

  • allows selection between the soon-to-be-deprecated privileged EXEC mode RP-based commands and the newer RMI IP-based mechanisms, and

  • derives RP IPs from RMI IPs after forming the HA pair, with restrictions on method transitions.

Additional reference information

  • When HA pairing is performed for the first time (without previous setup), devices do not have ROMMON variables for RP IP addresses.

  • After RMI-based HA pairing on a brand-new system:

    • RP IPs are derived from RMI IPs and used in HA pairing.

    • Privileged EXEC mode RP-based CLIs method of clearing and forming an HA pair is not allowed.

    • To view the ROMMON variables, use the show romvars command.

Command usage and method selection

  • You can still choose from the existing privileged EXEC mode RP-based commands or the RMI IP-based mechanisms. However, the privileged EXEC mode RP-based commands are deprecated.

  • If you use Cisco Catalyst Center, you can choose the privileged EXEC mode RP-based CLI mechanism till the Cisco Catalyst Center migrates to support the RMI.

  • If you choose privileged EXEC RP-based CLI mechanism, the RP IPs are configured the same way as in the 16.12 release.

Best practice: use RMI IP-based for fresh installations

Use the RMI IP-based mechanism for fresh installations, even though both RP-based and RMI methods may initially be available.

Software version considerations

Use the RMI IP-based mechanism for fresh installations, even though both RP-based and RMI methods may initially be available.

  • The RMI migration is supported from Cisco Catalyst Center, 2.3.3.x release version.

  • RMI-based High Availability requires Cisco IOS XE release version 17.3 or above.

Interoperability with Cisco Catalyst Center

  • If you use Cisco Catalyst Center, you can choose the privileged EXEC mode RP-based CLI mechanism till the Cisco Catalyst Center migrates to support the RMI.

  • The RMI migration is supported from Cisco Catalyst Center, 2.3.3.x release version.

Paired controllers

A paired controller is a high availability (HA) infrastructure configuration that

  • links two controllers to operate jointly for redundancy and failover,

  • allows seamless migration from traditional EXEC mode RP-based commands to RMI-based HA pairing, and

  • ensures controller identity and connectivity are maintained even when core pairing mechanisms are updated or reloaded.

Expanded explanation

When controllers are already in an HA pair, they continue to use existing EXEC mode RP-based commands unless Remote Management Interface (RMI) is enabled. Enabling RMI migrates the system to use RMI-derived HA pairing, overwriting any existing RP IPs with those derived from the RMI configuration. The HA pair remains stable immediately after this change, but the controllers only adopt the new IPs following their next reload.

RMI requires controllers to be reloaded for the changes to take effect. Once both controllers restart, they reestablish the HA pair using the new RMI-derived RP IPs. After pairing through RMI, EXEC mode RP-based commands are blocked, preventing configuration conflicts

Examples

  • Two controllers configured as a high availability pair, where enabling RMI changes the way their active-standby relationship is managed and what IPs are used for internal communication.

  • An active and standby controller pair that continues functioning during migration from legacy RP-IP pairing to RMI, without disruption until reload.

Counter-examples

  • Two standalone controllers operating independently without HA pairing cannot be considered paired controllers.

  • A controller pair where RMI is never configured and all management remains through EXEC mode RP-based commands does not benefit from RMI-derived features.

Analogy

Imagine a paired controller setup as two co-pilots flying an airplane together (the airplane represents your network environment). Traditionally, they use walkie-talkies (EXEC mode RP-based commands) to coordinate their flying activities. If you upgrade their communication system to headsets (RMI-based pairing), the co-pilots continue flying the plane using walkie-talkies until they both put on the new headsets (after a "reload" or restart). From that point onward, all their coordination happens via the more reliable and advanced headsets. The co-pilots' ability to work together—their partnership—remains unbroken throughout; it is only how they communicate and identify each other’s messages that changes, and only becomes effective after both are using the new headsets.

Upgrading from Cisco IOS XE 16.1.x to a Later Release

When upgrading a system, you have the following options:

  • Migrate while retaining the existing RP IP configuration: In this scenario, the current RP IP configuration remains unchanged, and future modifications will utilize EXEC mode RP-based commands.

  • Migrate after clearing the HA configuration: Here, you have the choice to use either the traditional EXEC mode RP-based commands or adopt the new RMI-based RP configuration. If the previous configuration is preserved, RMI will update the RP IPs with those derived from the RMI IPs.

Downgrade Scenario


Important

The downgrade scenario given below is not applicable for Cisco IOS XE Amsterdam 17.1.x.

In a downgrade scenario, only EXEC mode RP-based commands are available. The downgrade process may follow one of these paths:

  • If the upgraded system used the RMI-based RP configuration.

  • If the upgraded system continued to use the EXEC mode RP-based commands.

In the above cases, the downgraded system uses the EXEC mode RP-based commands to modify the configuration. However, the downgraded system will continue to use the new derived RP IPs.

In both of these cases, the system will revert to EXEC mode RP-based commands for configuration alterations, yet will still utilize the newly derived RP IPs.


Note

When you downgrade the Cisco Catalyst 9800 Series Wireless Controller to any version below 17.1 and if the mDNS gateway is enabled on the WLAN/RLAN/GLAN interfaces, the mdns-sd-interface gateway goes down after the downgrade.

To enable the mDNS gateway on the WLAN/RLAN/GLAN interfaces in 16.12 and earlier versions, use the following commands:

wlan test 1 test

mdns-sd gateway

To enable the mDNS gateway on the WLAN/RLAN/GLAN interfaces from version 17.1 onwards, use the following command:

mdns-sd-interface gateway

Configure Redundancy Management Interface (GUI)

Enable redundancy management for Cisco Catalyst 9800 Series Wireless Controllers using the graphical user interface (GUI).

Use this task to configure the redundancy management interface (RMI) and set up either RMI+RP or RP redundancy pairing on Cisco Catalyst 9800 Series Wireless Controllers. Configuring redundancy improves system availability and failover capabilities

Before you begin

Ensure that Wireless Management Interface (WMI) is available before configuring RMI + RP using the GUI.

Procedure

Step 1

In the Administration > Device > Redundancy window, perform the following:

  1. Set the Redundancy Configuration toggle button to Enabled to activate redundancy configuration.

  2. In the Redundancy Pairing Type field, select RMI+RP to perform RMI+RP redundancy pairing as follows:

    • In the RMI IP for Chassis 1 field, enter the RMI IP address for chassis 1.

    • In the RMI IP for Chassis 2 field, enter the RMI IP address for chassis 2.

  3. In the Redundancy Pairing Type field, select RP to perform RP redundancy pairing as follows:

    • In the Local IP field, enter an IP address for the local chassis.

    • In the Netmask field, enter the subnet mask assigned to all wireless clients.

    • From the HA Interface drop-down list, choose one of the HA interfaces.

      You can select the HA interface only for Cisco Catalyst 9800 Series Wireless Controllers.

    • In the Remote IP field, enter an IP address for the remote chassis.

  4. In the Keep Alive Timer field, enter an appropriate timer value (1–10 ×100 milliseconds).

  5. In the Keep Alive Retries field, enter an appropriate retry value (3–10 seconds).

  6. In the Active Chassis Priority field, enter a value.

Step 2

Click Apply and reload controllers.

The redundancy management interface is configured, and redundancy pairing is established based on your chosen method. The controller is now set up for improved high availability and failover.

Configure Redundancy Management Interface (CLI)

Purpose: Configure a Redundancy Management Interface (RMI) on Cisco Catalyst 9800 controllers using CLI commands to support high availability (HA) between two devices.

Context: Use this task when you want to set up high availability and redundancy between two Catalyst 9800 series controllers. The RMI coordinates HA communication and failover, ensuring service continuity in case of device failure.

Before you begin

  • Ensure both controllers are cabled and powered on.

  • Verify you have administrator access to both devices via CLI.

  • Gather the following information:

    • Chassis number (1 or 2 for each controller)

    • Desired chassis priority for HA (if overriding default)

    • A dedicated GigabitEthernet interface for HA communication (required for 9800-CL controllers)

    • Management VLAN and corresponding IP addresses for each chassis

Procedure

Step 1

chassis chassis-num priority chassis-priority

Example:

Device# chassis 1 priority 1

(Optional) Configures the priority of the specified device.

From Cisco IOS XE Gibraltar 16.12.x onwards, device reload is not required for the chassis priority to become effective.

  • chassis-num —Enter the chassis number. The range is from 1 to 2.

  • chassis-priority —Enter the chassis priority. The range is from 1 to 2. The default value is 1.

When both the devices boot up at the same time, the device with higher priority becomes active, and the other one becomes standby. If both the devices are configured with the same priority value, the one with the smaller MAC address acts as active and its peer acts as standby.

Step 2

chassis redundancy ha-interface GigabitEthernet interface-number

Example:

Device# chassis redundancy ha-interface 
                        GigabitEthernet 3

Creates an HA interface for your controller.

  • interface-number : GigabitEthernet interface number. The range is from 1 to 32.

This step is applicable only for Cisco Catalyst 9800-CL Series Wireless Controllers. The chosen interface is used as the dedicated interface for HA communication between the 2 controllers.

Step 3

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 4

redun-management interface vlan vlan-interface-number chassis chassis-number address ip-address chassis chassis-number address ip-address

Example:

Device(config)# redun-management interface                         
Vlan 200 chassis 1 address 9.10.90.147                         
chassis 2 address 9.10.90.149

Configures Redundancy Management Interface.

  • vlan-interface-number : VLAN interface number. The valid range is from 1 to 4094.

    Here, the vlan-interface-number is the same VLAN as the Management VLAN. That is, both must be on the same subnet.

  • chassis-number : Chassis number. The valid range is from 1 to 2.

  • ip-address : Redundancy Management Interface IP address.

Each controller must have a unique chassis number for RMI to form the HA pair. The chassis number can be observed as SWITCH_NUMBER in the output of show romvar command. Modification of SWITCH_NUMBER is currently not available through the web UI.

To disable the HA pair, use the no redun-management interface vlan chassis command.

Step 5

end

Example:

Device(config)# end

Returns to privileged EXEC mode.

Step 6

write memory

Example:

Device# write memory

Saves the configuration.

Step 7

reload

Example:

Device# reload

Reloads the controllers.

When the RMI configuration is done, you must reload the controllers for the configuration to take effect.

For Cisco Catalyst 9800-CL Wireless Controller VM, both the active and standby controllers reload automatically. In the case of hardware platforms, you should reload the active controller manually, as only standby the controller reloads automatically.

The redundancy management interface is configured. After reload, an HA pair is established between the two controllers, enabling redundancy and failover support.

Gateway Monitoring

Gateway Monitoring feature is a network management capability that

  • selects the gateway IP based on the static routes that match the RMI subnet using the broadest mask and least gateway IP

  • provides enhanced visibility and statistics related to gateway reachability and RMI state, and

  • simplifies troubleshooting and control over high availability (HA) and RMI functionality by offering detailed diagnostics.

Key aspects:

  • Gateway IP selection:

    • From Cisco IOS XE Amsterdam 17.2.1 onwards, the ip default-gateway gateway-ip command is deprecated for RMI gateway configuration.

    • The system automatically chooses a gateway IP by evaluating static routes and selecting the gateway that:

      • matches the RMI subnet,

    • If no matching static route exists, gateway failover does not operate—even if management gateway-failover is enabled.

Analogy: airport's air traffic control system

Gateway monitoring works like an airport’s air traffic control system. Instead of a pilot manually selecting a runway (like using the old ip default-gateway command), a central system automatically identifies the best runway based on current conditions (route matching, subnet mask, and lowest IP address). It then tracks the success or failure of each takeoff and landing (probe statistics and diagnostics), making sure the whole airport runs smoothly and efficiently while providing real-time updates and troubleshooting support when issues arise.

Configure Gateway Monitoring (CLI)

Enable and configure gateway monitoring on a device.

This task is typically performed to ensure that network devices can effectively monitor and manage gateway connections, facilitating smooth network operations and management. Gateway monitoring involves setting up a default gateway and enabling monitoring features.

Procedure

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

[no] management gateway-failover enable

Example:

Device(config)# management gateway-failover enable

Enables gateway monitoring. (Use the no form of this command to disable gateway monitoring.)

Step 3

end

Example:

Device(config)# end

Returns to privileged EXEC mode.

The gateway monitoring is enabled and configured, and the configuration changes are active.

What to do next

To save the configuration, use the write memory command.

Verifying the Gateway-Monitoring Configuration

To verify the status of the gateway-monitoring configuration on an active controller, run the following command:

Device# show redundancy states

my state = 13 -ACTIVE
peer state = 8 -STANDBY HOT
Mode = Duplex
Unit = Primary
Unit ID = 1

Redundancy Mode (Operational) = sso
Redundancy Mode (Configured) = sso
Redundancy State = sso
Maintenance Mode = Disabled
Manual Swact = enabled
Communications = Up

client count = 129
client_notification_TMR = 30000 milliseconds
RF debug mask = 0x0
Gateway Monitoring = Disabled
Gateway monitoring interval = 8 secs

To verify the status of the gateway-monitoring configuration on a standby controller, run the following command:

Device-stby# show redundancy states

my state = 8 -STANDBY HOT
peer state = 13 -ACTIVE
Mode = Duplex
Unit = Primary
Unit ID = 2

Redundancy Mode (Operational) = sso
Redundancy Mode (Configured) = sso
Redundancy State = sso
Maintenance Mode = Disabled
Manual Swact = cannot be initiated from this the standby unit
Communications = Up

client count = 129
client_notification_TMR = 30000 milliseconds
RF debug mask = 0x0
Gateway Monitoring = Disabled
Gateway monitoring interval = 8 secs

Verifying the Redundancy Management Interface Configuration

Verify the RMI IPv4 configuration.

Device# show running-config interface vlan management-vlan

Building configuration...

Current configuration : 109 bytes
!
interface Vlan90
ip address 9.10.90.147 255.255.255.0 secondary
ip address 9.10.90.41 255.255.255.0
end

To verify the interface configuration for a standby controller, use the following command:

Device-stby# show running-config interface vlan 90

Building configuration...
 
Current configuration : 62 bytes
!
interface Vlan90
ip address 9.10.90.149 255.255.255.0
end

To verify the chassis redundancy management interface configuration for an active controller, use the following command:

Device# show chassis rmi

Chassis/Stack Mac Address : 000c.2964.1eb6 - Local Mac Address
Mac persistency wait time: Indefinite
			H/W Current
Chassis# Role      Mac Address     Priority  Version  State  IP             RMI-IP
--------------------------------------------------------------------------------------------------------
*1       Active    000c.2964.1eb6  1         V02      Ready  169.254.90.147 9.10.90.147
2        Standby   000c.2975.3aa6  1         V02      Ready  169.254.90.149 9.10.90.149

To verify the chassis redundancy management interface configuration for a standby controller, use the following command:

Device-stby# show chassis rmi

Chassis/Stack Mac Address : 000c.2964.1eb6 - Local Mac Address
Mac persistency wait time: Indefinite
                                             H/W   Current
Chassis#   Role    Mac Address     Priority Version  State  IP              RMI-IP
------------------------------------------------------------------------------------------------
1         Active   000c.2964.1eb6     1      V02     Ready  169.254.90.147  9.10.90.147
*2        Standby  000c.2975.3aa6     1      V02     Ready  169.254.90.149  9.10.90.149

To verify the ROMMON variables on an active controller, use the following command:

Device# show romvar | include RMI

RMI_INTERFACE_NAME = Vlan90
RMI_CHASSIS_LOCAL_IP = 9.10.90.147
RMI_CHASSIS_REMOTE_IP = 9.10.90.149

To verify the ROMMON variables on a standby controller, use the following command:

Device-stby# show romvar | include RMI

RMI_INTERFACE_NAME = Vlan90
RMI_CHASSIS_LOCAL_IP = 9.10.90.149
RMI_CHASSIS_REMOTE_IP = 9.10.90.147

To verify the switchover reason, use the following command:

Device# show redundancy switchover history

Index  Previous  Current  Switchover             Switchover
       active    active   reason                 time
-----  --------  -------  ----------             ----------
   1       2        1     Active lost GW         17:02:29 UTC Mon Feb 3 2020