Cisco Catalyst 9800 Series Wireless Controller Software Configuration Guide, Cisco IOS XE Amsterdam 17.2.x

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 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

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.

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.

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

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.

System and Network Fault Handling

If the standby controller crashes, it reboots and comes up as the standby controller. Bulk sync follows causing the standby to become hot. If the active controller crashes, the standby becomes active. The new active controller assumes the role of primary and tries to detect a dual active.

The following matrices provide a clear picture of the conditions the controller switchover would trigger:

Table 2. System and Network Fault Handling
System Issues
Trigger	RP Link Status	Peer Reachability through RMI	Switchover	Result
Critical process crash	Up	Reachable	Yes	Switchover happens
Forced switchover	Up	Reachable	Yes	Switchover happens
Critical process crash	Up	Unreachable	Yes	Switchover happens
Forced switchover	Up	Unreachable	Yes	Switchover happens
Critical process crash	Down	Reachable	No	No action. One controller in recovery mode.
Forced switchover	Down	Reachable	N/A	No action. One controller in recovery mode.
Critical process crash	Down	Unreachable	No	Double fault – as mentioned in Network Error handling
Forced switchover	Down	Unreachable	N/A	Double fault – as mentioned in Network Error handling


RP Link	Peer Reachability Through RMI	Gateway From Active	Gateway From Standby	Switchover	Result
Up	Reachable	Reachable	Reachable	No SSO	No action
Up	Reachable	Reachable	Unreachable	No SSO	No action. Standby is not ready for SSO in this state, as it does not have gateway reachability. The standby is shown to be in standby-recovery mode. If the RP goes down, standby (in recovery mode) becomes active.
Up	Reachable	Unreachable	Reachable	SSO	Gateway reachability message is exchanged over the RMI + RP links. Active reboots so that the standby becomes active.
Up	Reachable	Unreachable	Unreachable	No SSO	With this, when the active SVI goes down, the standby SVI also goes down. A switchover is then triggered. If the new active discovers its gateway to be reachable, the system stabilizes in the Active - Standby Recovery mode. Otherwise, switchovers happen in a ping-pong fashion.
Up	Unreachable	Reachable	Reachable	No SSO	No action
Up	Unreachable	Reachable	Unreachable	No SSO	Standby is not ready for SSO in this state as it does not have gateway reachability. Standby moves in to recovery mode as LMP messages are exchanged over the RP link.
Up	Unreachable	Unreachable	Reachable	SSO	Gateway reachability message is exchanged over RP link. Active reboots so that standby becomes active.
Up	Unreachable	Unreachable	Unreachable	No SSO	With this, when the active SVI goes down, the standby SVI also goes down. A switchover is then triggered. If the new active discovers its gateway to be reachable, the system stabilizes in Active - Standby Recovery mode. Otherwise, switchovers happen in a ping-pong fashion.
Down	Reachable	Reachable	Reachable	No SSO	Standby becomes active with (old) active going in to active-recovery mode. Configuration mode is disabled in active-recovery mode. All interfaces will be ADMIN DOWN with the wireless management interface having RMI IP. The controller in the active-recovery mode will reload to become standby when the RP link comes UP.
Down	Reachable	Reachable	Unreachable	No SSO	Same as above.
Down	Reachable	Unreachable	Reachable	RP link down, then active loses GW, then there won't be any SSO. GW down, within 8 seconds, RP link goes down, then there would be a SSO.	Gateway reachability message is exchanged over RP+RMI links. Old-Active goes to active-recovery mode. The configuration mode is disabled in active-recovery mode. All interfaces will be ADMIN DOWN with the wireless management interface having RMI IP. The controller in active-recovery will reload to become standby (or standby-recovery if gateway reachability is still not available) when the RP link comes up.
Down	Reachable	Unreachable	Unreachable	No SSO	Standby goes to standby-recovery.
Down	Unreachable	Reachable	Reachable	SSO	Double fault – this may result in a network conflict as there will be two active controllers. Standby becomes active. Old active also exists. Role negotiation has to happen once the connectivity is restored and keep the active that came up last.
Down	Unreachable	Reachable	Unreachable	SSO	Same as above.
Down	Unreachable	Unreachable	Reachable	SSO	Same as above.
Down	Unreachable	Unreachable	Unreachable	SSO	Same as above.

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 3. 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.

Information About Redundancy Management Interface

The Redundancy Management Interface (RMI) is used as a secondary link between the active and standby Cisco Catalyst 9800 Series Wireless 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. The RMI is used for the following purposes:

Dual Active Detection
Exchange resource health information between controllers, for instance, gateway reachability status from either controller.
Gateway reachability is checked on the active and the standby controller through the RMI when the feature is enabled. It takes approximately 8 seconds to detect that a controller has lost gateway reachability.

Note

The RMI might trigger a switchover based on the gateway status on the controllers.
Cisco TrustSec is not supported on the RMI.

Active Controller

The primary address on the active controller is the management IP address. The secondary IPv4 address on the management VLAN is the RMI IP address for the active controller. Do not configure the secondary IPv4 addresses explicitly because a single secondary IPv4 address is configured automatically by RMI under the RMI.

Standby Controller

The standby controller does not have the wireless management IP configured; it has the RMI IP address configured as the primary IP address. 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.

Dual Stack Support on Management VLAN with RMI

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 Pairing

You should consider the following scenarios for HA pairing:

Fresh Installation
Already Paired Controllers
Upgrade Scenario
Downgrade Scenario

Dynamic HA pairing requires both the active controller and the standby controller to reload. However, dynamic HA pairing occurs on the Cisco Catalyst 9800-L Wireless Controller, Cisco Catalyst 9800-40 Wireless Controller, and the Cisco Catalyst 9800-80 Wireless Controller when one of them reloads and becomes the standby controller.

Note

Chassis numbers identify individual controllers. Unique chassis numbers must be configured before forming an HA pair.

HA Pairing Without Previous Configuration

When HA pairing is done for the first time, no ROMMON variables are found for the RP IP addresses. You can choose from the existing privileged EXEC mode RP-based commands or the RMI IP-based mechanisms. However, the privileged EXEC mode RP-based commands will be deprecated soon. 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 RP IPs are derived from the RMI IPs after an HA pair is formed. Also, the privileged EXEC mode RP-based CLI method of clearing and forming an HA pair is not allowed after the RMI IP-based HA mechanism is chosen.

Note

Although you can choose RP or RMI for a fresh installation, we recommend that you use RMI install method.
To view the ROMMON variables, use the show romvars command.

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

The following occurs when the RMI-based HA pairing is done on a brand-new system:

RP IPs are derived from RMI IPs and used in HA pairing.
Privileged EXEC mode RP-based CLIs are blocked.

Paired Controllers

If the controllers are already in an HA pair, the existing EXEC mode RP-based commands will continue to be used. You can enable RMI to migrate to the RMI-based HA pairing.

If the controllers are already paired and RMI is configured, it will overwrite the RP IPs with the RMI-derived IPs. The HA pair will not be disturbed immediately, but the controllers will pick up the new IP when the next reload happens. The RMI feature mandates a reload for the feature to be effective. When both the controllers are reloaded, they come up as a pair with the new RMI-derived RP IPs.

The following occurs when the RMI configuration is done:

The RP IPs derived from the RMI IPs are overwritten, and used for HA pairing.
If the active and standby controller already exist prior to HA pairing through the EXEC mode RP-based command mechanism, the pair is not interrupted.
When the pair reloads later, the new RP IPs are used.
EXEC mode RP-based commands are blocked.

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

A system that is being upgraded can choose to:

Migrate with the existing RP IP configuration intact—In this case, the existing RP IP configuration will continue to be used. The EXEC mode RP-based commands are used for future modifications.
Migrate after clearing the HA configuration—In this case, you can choose between the old (EXEC mode RP-based commands) and new RMI-based RP configuration methods.

Note

In case the older configuration is retained, the RMI configuration updates the RP IPs with the IPs derived from the RMI IPs.

Downgrade Scenario

Note

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

The downgrade scenario will have only the EXEC mode RP-based commands. The following are the two possibilities:

If the upgraded system used the RMI-based RP configuration.
If the upgraded system continued to use the EXEC mode RP-based commands.

Note

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.

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

Gateway Monitoring

From Cisco IOS XE Amsterdam 17.2.1 onwards, the method to configure the gateway IP has been modified. The ip default-gateway gateway-ip command is not used. Instead, the gateway IP is selected based on the static routes configured. From among the static routes configured, the gateway IP that falls in the same subnet as the RMI subnet is chosen. If no matching static route is found, gateway failover will not work (even if management gateway-failover is enabled).

Configuring Redundancy Management Interface (GUI)

Before you begin

Before configuring RMI + RP using GUI, ensure that WMI is available.

Procedure

Step 1

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

Set the Redundancy Configuration toggle button to Enabled to activate redundancy configuration.
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 RMI IP address for chassis 1.
- In the RMI IP for Chassis 2 field, enter RMI IP address for chassis 2.

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 Local IP.
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 interface.

Note

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

In the Remote IP field, enter an IP address for Remote IP.

In the Keep Alive Timer field, enter an appropriate timer value. The valid range is between 1 and 10 (x100 milliseconds).
In the Keep Alive Retries field, enter an appropriate retry value. The valid range is between 3 and 10 seconds.
In the Active Chassis Priority field, enter a value.

Step 2

Click Apply and reload controllers.

Configuring Redundancy Management Interface (CLI)

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 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.

Note

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.

Note

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.

Note

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.

Note

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.

Configuring Gateway Monitoring (CLI)

Procedure

Command or Action Purpose

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.

Note

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

Bias-Free Language

Results

Chapter: High Availability

High Availability

Feature History for High Availability

Information About High Availability

Prerequisites for High Availability

External Interfaces and IPs

HA Interfaces

Restrictions on High Availability

Configuring High Availability (CLI)

Before you begin

Procedure

Example:

Example:

Example:

Example:

Disabling High Availability

System and Network Fault Handling

Verifying High Availability Configurations

Verifying AP or Client SSO Statistics

Verifying High Availability

Configuring a Switchover

Procedure

Example:

Information About Redundancy Management Interface

Active Controller

Standby Controller

Dual Stack Support on Management VLAN with RMI

RMI-Based High-Availability Pairing

HA Pairing Without Previous Configuration

Paired Controllers

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

Downgrade Scenario

Gateway Monitoring

Configuring Redundancy Management Interface (GUI)

Before you begin

Procedure

Configuring Redundancy Management Interface (CLI)

Procedure

Example:

Example:

Example:

Example:

Example:

Example:

Example:

Configuring Gateway Monitoring (CLI)

Procedure

Example:

Example:

Example:

Verifying the Gateway-Monitoring Configuration

Verifying the Redundancy Management Interface Configuration

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