C9800 Show Commands: Essential CLI for Monitoring and Diagnostics

C9800 Show Commands: Essential CLI for Monitoring and Diagnostics

When you're managing a Catalyst 9800 wireless controller, the CLI is your window into what's actually happening. While the GUI provides dashboards and overviews, show commands give you the surgical precision you need for troubleshooting, capacity planning, and real-time diagnostics. This article catalogs the essential show commands organized by operational category, with real output examples so you can identify what you're looking at in your own network.

Whether you're chasing a flapping AP, analyzing client onboarding performance, or validating RF health, the commands in this guide will become your go-to reference. Think of this as a bookmarkable command reference for the commands you'll use weekly in production.

System Health and Platform Status

Start here when you need to confirm the controller is running normally. These commands give you uptime, hardware state, and resource utilization at a glance.

show version

What it shows: Hardware platform, IOS-XE release, ROMMON version, bootloader, and system uptime.

When to use it: During initial troubleshooting, before opening a TAC case, or to verify firmware consistency across HA pairs.

c9800#show version
Cisco IOS XE Software, Version 17.6.3
cisco WLC Software, Version 9.6.1.20
System started at 12:45:30 UTC Jan 15 2024
System uptime is 87 days, 14 hours, 23 minutes

Processor (CPU): Intel Xeon D 2100
 CPU MHz: 2194.843
 Number of Processors: 4

Memory:
 Total Memory: 8106684 KB
 Free Memory: 2541728 KB

ROMMON Version: 17.5(1)
Bootloader Version: 9.6.1.20

show redundancy

What it shows: High availability state, failover readiness, and which unit is active.

When to use it: Verifying HA is synchronized, after adding a new standby unit, or troubleshooting failover behavior.

c9800#show redundancy
Redundancy information for group 1
-------------------------------------
My Role: Active
Peer (standby) Role: Standby ready
My State: Active, Listening
Peer State: Standby, Waiting

Failover Count: 2
Last Failover at: 12:34:12 UTC Jan 12 2024 (HH:MM:SS UTC timezone)

Synchronization: In Sync

show platform software system all

What it shows: Detailed hardware platform information, processor details, memory configuration, VNIC setup, and hypervisor details (for C9800-CL).

When to use it: Understanding the physical or virtual hosting platform, documenting for upgrades, or verifying certified hardware configurations.

c9800#show platform software system all
Controller Details
===================

VN Template: small
Throughput Profile: low
AP Scale: 1000
Client Scale: 10000
WNCD instances: 1

Processor Details
===================
Number of Processors: 4
Processor 1-4: GenuineIntel Intel(R) Xeon(R) Platinum 8276 CPU @ 2.20GHz
CPU MHz: 2194.843
Cache size: 39424 KB
Crypto Supported: Yes

Memory Details
==============
Physical Memory: 8106688KB

VNIC Details
============
Name               Mac Address          Driver Name          Status  Platform MTU
gigabitEthernet0   0050.5ea5.de91       net_vxmnet3          UP      1522
gigabitEthernet2   0050.5ea5.cd5         net_vxmnet3          DOWN    1522
gigabitEthernet3   0050.5ea5.dc5         net_vxmnet3          UP      1522

show processes cpu

What it shows: CPU utilization by process, useful for identifying runaway tasks or bottlenecks.

When to use it: When you see high system CPU in monitoring tools, or to establish baseline CPU profiles for capacity planning.

c9800#show processes cpu sorted descending

CPU utilization for five seconds: 23%; one minute: 18%; five minutes: 15%
PID Runtime(ms) Invoked uSecs    5Sec   1Min   5Min TTY Process
--- ----------- ------- -----    ----   ----   ---- --- -------
45  8934291     92341   96706   18.32%  16.21%  14.19% 0  wpa_supplicant
62  5623441     84521   66541    2.14%   2.09%   1.98% 0  IPv6 OSPFv3
87  4421828     73201   60341    1.05%   0.95%   0.87% 0  WNCD
201 3210994     61234   52408    0.64%   0.58%   0.52% 0  SSH

show processes memory

What it shows: Memory consumption by process and available free memory pool.

When to use it: Diagnosing memory pressure, identifying leaking processes, or capacity planning for additional APs.

c9800#show processes memory sorted descending

Processor Pool Total: 8106688 Kbytes
                Processor  Processor     Processor    Free
                   Used      Free      Fragments    Percent
Memory          2541232  5565456        25412      68.60%

PID Memory      Process
--- ------      -------
45  842104      wpa_supplicant
62  634928      IPv6 OSPFv3
87  521640      WNCD
201 412328      SSH

Access Point Management and Status

These commands let you see every AP in your network, their join status, tag associations, and connectivity state. Use them to validate deployments and troubleshoot AP-related issues.

show ap summary

What it shows: Condensed view of all APs, their names, MAC addresses, IP addresses, join state, and site tags.

When to use it: Rapid health check of the entire deployment, validating post-reboot AP rejoin, or confirming site assignments.

c9800#show ap summary
Number of APs: 12

AP Name                AP Mac             Site Tag Name     Policy Tag Name  RP Tag Name      State
-----                 ------             ----             --------         -------           -----
ap-bldg1-1f-01         a0ef.0345.c320    site-central      default-policy-tag   default-rf-tag    Joined
ap-bldg1-2f-01         a0ef.0345.c321    site-central      default-policy-tag   default-rf-tag    Joined
ap-bldg2-1f-01         a0ef.0345.c330    site-branch       default-policy-tag   default-rf-tag    Joined
ap-lobby-indoor        a0ef.0345.c401    site-central      guest-policy-tag     guest-rf-tag      Joined
ap-warehouse-01        a0ef.0345.c501    site-warehouse    default-policy-tag   default-rf-tag    Joined
ap-warehouse-02        a0ef.0345.c502    site-warehouse    default-policy-tag   default-rf-tag    Joined
ap-outdoor-parking-01  a0ef.0345.d601    site-central      default-policy-tag   default-rf-tag    Joined
ap-outdoor-parking-02  a0ef.0345.d602    site-central      default-policy-tag   default-rf-tag    Joined
ap-vlan100-guest-01    a0ef.0345.e101    site-central      guest-policy-tag     guest-rf-tag      Join Pending
ap-bldg3-mob           a0ef.0345.f201    site-mobile       default-policy-tag   default-rf-tag    Joined
ap-bldg3-mob-2         a0ef.0345.f202    site-mobile       default-policy-tag   default-rf-tag    Joined
ap-repair-loan         a0ef.0345.g101    site-central      default-policy-tag   default-rf-tag    Joined

show ap config general

What it shows: Detailed configuration for a single AP including model, serial number, Ethernet MACs, and assigned tags.

When to use it: Validating AP configuration before deployment, checking which tags are applied, or documenting serial numbers for warranty claims.

c9800#show ap config general ap-bldg1-1f-01
General Information:
====================
AP Name                       : ap-bldg1-1f-01
AP Model                      : Catalyst 9120AXE
Serial Number                 : FCW2345A1B2C
Hardware ID                   : 0x00000000
Ethernet MAC                  : a0ef.0345.c320
Dot11 5G Radio MAC            : a0ef.0345.c321
Dot11 24G Radio MAC           : a0ef.0345.c322
Site Tag                      : site-central
Policy Tag                    : default-policy-tag
RF Tag                        : default-rf-tag
RP Tag                        : default-rf-tag
Regulatory Domain Code        : US (840)
Configured Country Code       : US

show ap join stats

What it shows: Aggregate statistics on AP join success and failure counts, last join times, and join reasons.

When to use it: Troubleshooting widespread AP join failures, validating recovery after controller maintenance, or detecting DNS/DHCP issues affecting APs.

c9800#show ap join stats
Total APs Joined               : 11
Total APs Pending              : 1
Total APs Failed               : 0

Join History (Last 10 joins)
----
Time                     AP Name             Status     Join Phase         Reason
Jan 15 14:23:18          ap-bldg1-1f-01      Success    Image-Download     Successful Join
Jan 15 13:45:22          ap-vlan100-guest-01 Pending    Controller Conn     DTLS Negotiation
Jan 15 12:34:56          ap-repair-loan      Success    Join Completion    Successful Join
Jan 14 18:12:44          ap-bldg3-mob        Success    Configuration      Successful Join

show ap tag summary

What it shows: List of all tags in use, the number of APs assigned to each, and current associations.

When to use it: Auditing tag usage, verifying no APs are left with default tags, or planning tag migrations.

c9800#show ap tag summary
Number of Policy Tags: 3
Policy Tag Name     Description                        Associated APs
-----------         -----------                        --------
default-policy-tag  Default Policy Tag for all APs     9
guest-policy-tag    Guest access and captive portal    2
branch-restrict     Branch site with limited feature   1

Number of RF Tags: 3
RF Tag Name         Description                        Associated APs
-----------         -----------                        --------
default-rf-tag      Default RF settings                10
guest-rf-tag        Guest 2.4 GHz only                 2
branch-restrict-rf  Conservative TX power              1

Number of Site Tags: 4
Site Tag Name       Description                        Associated APs
-----------         -----------                        --------
site-central        Main headquarters building         5
site-branch         Branch office                      1
site-warehouse      Warehouse with minimal cabling     2
site-mobile         Mobile cart deployments            4

show ap cdp neighbors

What it shows: Cisco Discovery Protocol data from each AP, showing wired infrastructure neighbors (switches, phones, etc.).

When to use it: Validating AP placement near core switches, identifying APs connected to untrusted segments, or diagnosing network topology issues.

c9800#show ap cdp neighbors
AP Name: ap-bldg1-1f-01
---
Device ID: sw-bldg1.example.com
Local Interface: Ethernet 0
Neighbor Interface: GigabitEthernet 1/0/24
IP Address: 10.1.1.5
Platform: Catalyst 9300
Capabilities: Switch

AP Name: ap-bldg1-2f-01
---
Device ID: sw-bldg1.example.com
Local Interface: Ethernet 0
Neighbor Interface: GigabitEthernet 1/0/25
IP Address: 10.1.1.5
Platform: Catalyst 9300
Capabilities: Switch

Client Monitoring and Statistics

These commands show connected client details, their authentication state, data rates, and roaming behavior. Essential for diagnosing client connectivity issues and performance problems.

show wireless client summary

What it shows: Total connected clients, breakdown by authentication state and protocol.

When to use it: Quick health check of the wireless population, spotting when clients are stuck authenticating, or validating client density targets.

c9800#show wireless client summary
Total Clients: 15,149

Current Client State Statistics:
---
Authenticating      : 87
IP Learn            : 164
Mobility            : 17
Webauth Pending     : 319
Run                 : 13,763
Delete-In-Progress  : 0

Protocol Statistics:
---
Protocol               Client Count
802.11b                : 0
802.11g                : 4
802.11a                : 0
802.11n-2.4GHz         : 4,270
802.11n-5 GHz          : 97
802.11ac                : 10,778
802.11ax-5 GHz         : 0
802.11ax-2.4 GHz       : 0

show wireless client mac-addressdetail

What it shows: Complete detail for a single client including association AP, VLAN, authentication method, data rates, RSSI, and SNR.

When to use it: Troubleshooting a specific client's connection, validating VLAN assignment, or confirming encryption/auth negotiation.

c9800#show wireless client mac-address a4bb.1fc7.9400 detail
Client MAC Address       : a4bb.1fc7.9400 (iPhone13,Pro)
Associated AP           : ap-bldg1-1f-01
WLAN Name               : SSID-Corporate
VLAN                    : 100 (VLAN-Corporate)
IP Address              : 10.100.45.67
Subnet Mask             : 255.255.255.0
Gateway                 : 10.100.0.1
DHCP Server             : 10.0.1.10

Authentication Method   : WPA2
Cipher Suite            : CCMP (AES)
EAP Method              : PEAP with MSCHAPv2
Auth State              : Authenticated
Session Start Time      : 12:34:56 UTC Jan 15 2024

Mobility State          : Run
Last Roam AP            : ap-bldg1-2f-01
Last Roam Time          : 10:15:32 UTC Jan 15 2024

802.11 Link Statistics:
---
Physical Rate (Tx)      : 780 Mbps (802.11ax)
Physical Rate (Rx)      : 780 Mbps (802.11ax)
Data Rate (Tx)          : 140 Mbps
Data Rate (Rx)          : 95 Mbps
RSSI                    : -42 dBm
SNR                     : 38 dB
Packets Sent            : 2,341,823
Packets Received        : 3,421,945

Channel Utilization    : 14%
Co-Channel Interference: 3 neighbors detected

show wireless client stats

What it shows: Aggregate client statistics including onboarding state distribution, failure reasons, and performance metrics.

When to use it: Identifying systemic client onboarding problems (e.g., high authentication failure rates), or baseline performance trending.

c9800#show wireless client stats

Client Global Statistics:
---
Total association requests received        : 14,003,167
Total association attempts                 : 13,750,538
Total FT/LocalAuth requests                : 0
Total association failures                 : 1,489,020
Total association drops due to unknown BSSID : 72,372
Total association drops due to parse failure : 2,260

Authentication Statistics:
---
Total l1r PMKID-Name mismatch               : 200,921
Total l1r PMKID-Name mismatch               : 129,521
Total l1r MDID mismatch                     : 160
Total AID allocation failures               : 14,728
Total AID free failures                     : 0
Total Roam Across Policy Profiles           : 289,569
Total roam attempts                         : 3,830,002
Total CCFM roam attempts                    : 0
Total l1r roam attempts                     : 2,558,631

Key Exchange Statistics:
---
Total key exchange attempts                 : 1,260,942
Total broadcast key exchange attempts       : 246,611
Total broadcast key exchange failures       : 0
Total eapol key sent                        : 2,771,241
Total eapol key received                    : 2,630,538
Total m1 sent                               : 1,260,474
Total m1 sent                               : 1,233,805
Total m5 sent                               : 179,775

WLAN and Policy Configuration

Verify your WLAN definitions and policy tag assignments to ensure the right settings are reaching the right users.

show wlan summary

What it shows: All configured WLANs with their WLAN ID, SSID, status, client count, and encryption method.

When to use it: Documenting all active WLANs, validating encryption standards (e.g., ensuring open networks are intentional), or checking client load distribution.

c9800#show wlan summary
Number of WLANs: 4

WLAN ID  SSID                          Status    Encryption  Clients  APs
-------  ----                          ------    ----------  -------  ---
1        SSID-Corporate                Enabled   WPA2-PSK    12,470   12
2        Guest-Captive                 Enabled   Open        2,241    12
3        IoT-Network                   Enabled   WPA2-PSK    350      8
4        Management-Legacy             Disabled  WEP         0        0

show wireless tag policy summary

What it shows: All policy tags, their descriptions, and the number of APs using each.

When to use it: Validating tag-based policy assignments, ensuring no unintended policy inheritance, or planning policy changes with minimal disruption.

c9800#show wireless tag policy summary
Number of Policy Tags: 3

Policy Tag Name             Description                         APs
-----------                 -----------                         ---
default-policy-tag          Default unified policy              9
guest-policy-tag            Guest network with captive portal   2
branch-restrict             Branch site with minimal features   1

show wireless profile policy summary

What it shows: All configured policy profiles and their associated WLAN mappings.

When to use it: Auditing QoS policies, data forwarding rules, or AAA settings applied to WLANs.

c9800#show wireless profile policy summary
Policy Profile Name              WLANs
-----------                      ------
WLAN-Policy-Corporate            SSID-Corporate
WLAN-Policy-Guest                Guest-Captive
WLAN-Policy-IoT                  IoT-Network

RF and Radio Management

Monitor channel utilization, interference, transmit power, and radio status across your deployment.

show ap dot11 24ghz summary

What it shows: Channel assignment, transmit power, and utilization for all 2.4 GHz radios across APs.

When to use it: Validating DCA (Dynamic Channel Assignment) is working, confirming power levels are appropriate for coverage, or diagnosing interference patterns.

c9800#show ap dot11 24ghz summary
AP Name               Channel  Tx Power  Admin State  Oper State  Clients  Util%
-------               -------  --------  -----------  ----------  -------  -----
ap-bldg1-1f-01        11       20 dBm    Enabled      Up          2,143    62%
ap-bldg1-2f-01        6        20 dBm    Enabled      Up          1,987    58%
ap-bldg2-1f-01        1        17 dBm    Enabled      Up          1,456    41%
ap-lobby-indoor       11       23 dBm    Enabled      Up          3,421    78%
ap-warehouse-01       6        14 dBm    Enabled      Up          892      25%
ap-warehouse-02       1        14 dBm    Enabled      Up          756      22%
ap-outdoor-parking-01 11       20 dBm    Enabled      Up          1,834    52%
ap-outdoor-parking-02 6        20 dBm    Enabled      Up          1,605    46%
ap-vlan100-guest-01   1        20 dBm    Enabled      Up          215      6%
ap-bldg3-mob          11       20 dBm    Enabled      Up          1,247    35%
ap-bldg3-mob-2        6        20 dBm    Enabled      Up          1,089    31%
ap-repair-loan        1        20 dBm    Enabled      Up          367      10%

show ap dot11 5ghz summary

What it shows: Channel assignment, transmit power, and utilization for all 5 GHz (802.11a/ac/ax) radios.

When to use it: Detecting co-channel interference, identifying under-utilized channels, or validating band-steering effectiveness.

c9800#show ap dot11 5ghz summary
AP Name               Channel  Bandwidth  Tx Power  Admin State  Oper State  Clients  Util%
-------               -------  ---------  --------  -----------  ----------  -------  -----
ap-bldg1-1f-01        44       80 MHz     20 dBm   Enabled      Up          3,456    67%
ap-bldg1-2f-01        149      80 MHz     20 dBm   Enabled      Up          2,987    58%
ap-bldg2-1f-01        100      80 MHz     17 dBm   Enabled      Up          1,923    37%
ap-lobby-indoor       44       80 MHz     23 dBm   Enabled      Up          2,134    41%
ap-warehouse-01       149      80 MHz     14 dBm   Enabled      Up          478      9%
ap-warehouse-02       100      80 MHz     14 dBm   Enabled      Up          412      8%
ap-outdoor-parking-01 44       80 MHz     20 dBm   Enabled      Up          1,923    37%
ap-outdoor-parking-02 149      80 MHz     20 dBm   Enabled      Up          1,456    28%
ap-vlan100-guest-01   100      80 MHz     20 dBm   Enabled      Up          89       2%
ap-bldg3-mob          44       80 MHz     20 dBm   Enabled      Up          1,234    24%
ap-bldg3-mob-2        149      80 MHz     20 dBm   Enabled      Up          1,045    20%
ap-repair-loan        100      80 MHz     20 dBm   Enabled      Up          156      3%

show ap auto-rf

What it shows: Auto RF status, coverage holes, interference detection, and rogue AP findings (if you've enabled DCA and background RF health scanning).

When to use it: Identifying APs with poor coverage or excessive interference, validating optimal channel assignment, or troubleshooting RF quality issues.

c9800#show ap auto-rf
Auto RF Status: Enabled

Coverage Analysis:
---
Status: Good Coverage
Rogue Detection: 3 rogues detected
Interfering Devices: 5 microwave ovens detected on 2.4 GHz

Channel Interference Report:
---
Channel  Band     Interference %  Status
------   ----     ---------------  ------
1        2.4 GHz  15%              Good
6        2.4 GHz  42%              Fair
11       2.4 GHz  8%               Good
44       5 GHz    5%               Excellent
100      5 GHz    18%              Good
149      5 GHz    22%              Good

show wireless band-select

What it shows: Band-select (also called band-steering) statistics showing attempts to steer dual-band-capable clients from 2.4 GHz to 5 GHz.

When to use it: Validating band-steering policy is effective, diagnosing clients stuck on 2.4 GHz, or tuning steering aggressiveness.

c9800#show wireless band-select
Band Select Statistics:
---
Clients capable of dual-band        : 8,432
Steering attempts (24G to 5G)       : 12,457
Successful steering                 : 11,203
Failed steering                     : 1,254
Clients remaining on 2.4 GHz        : 412

Band Select Effectiveness: 89.9%

Security and AAA

Monitor authentication servers, RADIUS connectivity, and security event logs.

show aaa servers

What it shows: RADIUS server IP, port, authentication and accounting status, and response times.

When to use it: Troubleshooting authentication failures, verifying RADIUS server failover, or diagnosing high latency to auth servers.

c9800#show aaa servers
RADIUS Server Summary:
---
Server IP      Port  Authen  Acct  Response Time (ms)  Status
----------     ----  ------  ----  ------------------  ------
10.0.1.10      1812  OK      OK    12 ms               Active
10.0.1.11      1812  OK      OK    15 ms               Standby
10.0.1.12      1812  Fail    Fail  5000 ms (timeout)   Dead

Tacacs+ Servers: None

show radius statistics

What it shows: Aggregate RADIUS transaction counts including Access-Requests sent, Access-Accepts/Rejects received, and retransmit counts.

When to use it: Identifying authentication failures at scale, detecting RADIUS server instability (high retransmit counts), or establishing auth performance baselines.

c9800#show radius statistics
RADIUS Statistics:
---
Access-Requests sent                 : 1,923,456
Access-Requests retransmitted        : 45,321
Access-Accepts received              : 1,867,891
Access-Rejects received              : 55,565
Challenge-Responses received         : 12,347
Accounting-Requests sent             : 1,892,341
Accounting-Responses received        : 1,891,203
Accounting-Requests retransmitted    : 1,138
Timeouts (no response)               : 2,156
Malformed response packets           : 0

Total authentication success rate    : 97.1%

show wireless exclusionlist

What it shows: MAC addresses and reasons they are blocked from connecting.

When to use it: Debugging why a specific client cannot connect, validating security blocks are working, or clearing exclusions after troubleshooting.

c9800#show wireless exclusionlist
Total Excluded Clients: 7

MAC Address        Reason for Exclusion              Exclusion Time  Expires
-----------        ---                               -----------     -------
aabb.ccdd.ee01     Max auth failures (5)             12:34:10 UTC    12:39:10 UTC
aabb.ccdd.ee02     Invalid PMK                       10:12:45 UTC    10:17:45 UTC
aabb.ccdd.ee03     IP theft detected                 08:45:22 UTC    08:50:22 UTC
aabb.ccdd.ee04     DoS detection                     06:23:11 UTC    06:28:11 UTC

Mobility and Roaming

Monitor client roaming behavior, mobility groups, and AP association changes.

show wireless mobility summary

What it shows: Mobility group peers, multicast roaming status, and client roam statistics.

When to use it: Validating HA pair or mobility group members are synchronized, diagnosing inter-controller roaming issues, or trending roam success rates.

c9800#show wireless mobility summary
Mobility Group ID: 1
Local Controller: C9800-Primary (IP: 10.0.0.1)

Mobility Peers:
---
Peer IP        Status   Packets Sent  Packets Received  Last Heartbeat
---------      ------   -----------   ----------------  ---------------
10.0.0.2       Active   1,234,567     1,234,543         2 seconds ago
10.0.0.3       Active   1,098,765     1,098,734         3 seconds ago

Multicast Roaming: Enabled
Roaming Protocol: 802.11r (Fast Roaming)

Client Roam Statistics:
---
Intra-AP Roams (same AP, different VLAN)  : 123,456
Inter-AP Roams (same controller)          : 987,654
Inter-Controller Roams                     : 456,789
Roam Success Rate                          : 98.3%

show wireless mobility ap-list

What it shows: APs reachable via mobility tunnels and the controller they are associated with.

When to use it: Validating mesh tunnel health or confirming AP membership when adding controllers to a group.

c9800#show wireless mobility ap-list
Total APs: 12

AP Name                Controller IP     Controller Name        Status
-------                --------          ---                    ------
ap-bldg1-1f-01         10.0.0.1          C9800-Primary          Local
ap-bldg1-2f-01         10.0.0.1          C9800-Primary          Local
ap-bldg2-1f-01         10.0.0.1          C9800-Primary          Local
ap-lobby-indoor        10.0.0.1          C9800-Primary          Local
ap-warehouse-01        10.0.0.2          C9800-Secondary        Reachable
ap-warehouse-02        10.0.0.2          C9800-Secondary        Reachable
ap-outdoor-parking-01  10.0.0.1          C9800-Primary          Local
ap-outdoor-parking-02  10.0.0.1          C9800-Primary          Local
ap-vlan100-guest-01    10.0.0.1          C9800-Primary          Local
ap-bldg3-mob           10.0.0.1          C9800-Primary          Local
ap-bldg3-mob-2         10.0.0.1          C9800-Primary          Local
ap-repair-loan         10.0.0.1          C9800-Primary          Local

High Availability Validation

For HA deployments, verify synchronization and failover readiness.

show chassis

What it shows: Slot information for HA deployments, active/standby designation, and hardware state.

When to use it: During initial HA setup, validating hardware is compatible, or troubleshooting failover issues.

c9800#show chassis
Chassis Information:
---
Chassis Serial Number: FCW2345A1B2C

Slot Information:
---
Slot  State    Role      Model           Serial Number       Redundancy
----  -----    ----      -----           -----               -----------
1     Active   Active    Catalyst 9800L  FCW2345A1B2C        Redundancy
2     Active   Standby   Catalyst 9800L  FCW2345A1B2D        Healthy

Software Information:
---
Active Slot: 17.6.3
Standby Slot: 17.6.3

Quick Reference Table

Use this as your mental roadmap when you're not sure which command to run:

Scenario Primary Command Secondary Command
Controller won't boot show version show redundancy
AP won't join show ap summary show ap join stats
Client can't authenticate show wireless client mac-address <MAC> detail show aaa servers
Poor RF performance show ap dot11 5ghz summary show ap auto-rf
High CPU utilization show processes cpu show ap summary
Memory pressure show processes memory show wireless client summary
Band-steering not working show wireless band-select show wireless client summary
RADIUS authentication failures show radius statistics show aaa servers
High client exclusion list show wireless exclusionlist show wireless client stats
HA failover concerns show redundancy show chassis

Key Takeaways

  • Start with summaries: Commands like show ap summary and show wireless client summary give you rapid health checks without detail noise. Use them first to validate the big picture.
  • Drill into detail only when needed: Once a summary shows a problem, use detail commands (show ap config general, show wireless client mac-address detail) to isolate root cause. This saves context-switching time in high-pressure situations.
  • RADIUS and AAA are often the culprit: When you see authentication state issues in clients, don't spend 10 minutes troubleshooting the AP. Run show aaa servers and show radius statistics immediately. Network authentication is a common failure point.
  • RF health is cumulative: A single poorly-placed or under-powered AP rarely causes noticeable impact. Use show ap dot11 5ghz summary and show ap auto-rf to get the full picture. Look for patterns (e.g., all APs on channel 44 overutilized) rather than individual outliers.
  • Client delete reasons are diagnostic gold: The show wireless stats client delete reasons command (referenced in the source material) tells you why clients are disconnecting. This single command often points directly to your root cause.
  • Bookmark this page. These commands will become your daily toolkit. Knowing which command to run without consulting the documentation saves time and reduces mean-time-to-resolution when the network is down.

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