簡介

本文描述用於排除9800 AP加入或斷開問題故障的系統方法和命令清單。

必要條件

思科建議您瞭解以下主題：

Cisco WLC 9800基礎知識
Cisco Wave2和/或11AX AP的基本知識

拓撲

此故障排除流程適用於以本地模式連線的AP或以分支站點的flexconnect模式連線的AP。

從WLC收集的通用輸出

1.您可以開始驗證AP的數量是否與連線到WLC的預期的AP數量相匹配。並檢視WLC日誌以瞭解AP斷開情況。
確定您是否缺少任何AP，以及在日誌中是否觀察到AP同時斷開連線或始終保持相同的AP連線/斷開

sh ap image summary | i Number of APs !!Check if number of APs matches with number we expect
sh log | i AP Event: !!Check if APs are disconnecting at same time, or exist any pattern for APs connecting/disconnecting.

2.您可以獲取所有AP清單並檢查是否缺少AP。識別運行時間更短、Assoc運行時間更短的AP，以幫助識別是否存在AP重新載入或重新連線到capwap。
如果AP正在重新載入，您可以檢查是否有具有相似正常運行時間的AP，並檢查這些AP是否位於同一交換機中。如果您看到的AP運行時間較長且關聯時間較低，則需要檢查是否對可能導致capwap重新啟動的AP進行了更改，或者是否由於重新傳輸而導致capwap擺動。您還可以檢查是否有任何AP崩潰。

show ap uptime !! Check Up Time vs Assoc Up Time. Check for patterns
show ap cdp nei !! Identify if all APs with similar Up Time were in same switch.
show ap crash !! Check if there are any AP crashes.
dir all | i crash !! Find AP crashes stored in WLC.

3.您可以檢查所有AP連線/斷開連線歷史事件和斷開連線原因。您可以瞭解斷開原因是否與所有AP類似，以及連線是在哪個階段斷開的。
確定主要斷開原因以及是否存在這些斷開的時間模式。

show wireless stats ap history !! Find connect/disconnect events, time for those events, disconnect reason and count.
show wireless stats ap discovery !! Find discovery requests been received by WLC and time for those discovery requests
show wireless stats ap join summary !! Find status of the AP, last disconnection reason and in which phase disconnection occurred.

4.在DTLS階段出現錯誤時，我們可以檢查哪種型別的證書和密碼用於AP DTLS握手。

show wireless certification config !! Check DTLS version and cipher suite
show wireless management trustpoint !! Type of certificate used
show wireless dtls connections !! Show if DTLS is established for capwap control/data ports used

來自特定AP的WLC的特定輸出

5.現在，您可以關注一些有問題的具體AP。首先需要找到該AP的乙太網MAC和無線電MAC。檢查該AP的歷史記錄和永遠線上跟蹤
使用show命令可顯示事件摘要，並附有時間參考、AP關聯的不同階段，從中可觀察到故障、重新啟動或斷開的原因。
您可以瞭解WLC是否由於映像升級而重新啟動AP。或者AP由於保持連線故障而斷開連線。
然後使用always-on-tracing來獲取有關AP發生情況的更多詳細資訊，其中顯示事件序列。使用show命令時間參考，您可以集中注意該時間前後發生的事件。

Collecting show tech wireless for concrete AP provides us config details, tag assigment, info about model, radios channels...

show wireless stats ap history mac-address Ethernet_MAC@ !!Check type of event and time for the event and disconnect reason and count for specific AP.
show wireless stats ap mac Radio_MAC@ discovery detailed !!Check number of discovery request/responses, discovery failures and type for last working discovery and non working discovery.
show wireless stats ap mac Radio_MAC@ join detailed !!Counters for different phases discovery, dtls, join, config, data dtls. Also shows last reboot type and reason. Disconnect type and reason.
show logging profile wireless start last X days filter mac 
     
     
       !!Always-on-tracing for this AP shows more detailed events errors stored in the WLC trace database. Config changes, radio events, association/disassociation events. show tech wireless ap name 
      
        !! Config details, tag, radio info channels/txpower, SSIDs, ... 
       
     

6.如果觀察到，不同交換機中的多個AP大約在同一時間斷開，則可以確認所有斷開的AP是否位於同一視窗中。
如果是這種情況，您可以檢查wncd CPU使用率，檢視是否因為高wncd CPU使用率和WLC無法處理從AP接收的包而斷開連線。

show wireless loadbalance ap affinity mac Ethernet_MAC@ !!Check wncd assigned to concrete AP mac address, we can also get wncd for concrete site-tag
show wireless loadbalance ap affinity wncd <0-7> !!Other option is to check all APs assigned to a concrete wncd.
sh proc cpu platform | i wncd !! Check CPU utilization per wncd

來自具體AP的WLC和AP的高級日誌

7.如果使用以前的資訊無法確定AP加入的原因，則需要捕獲ra-trace和資料包捕獲以及AP調試，以便在下次事件時可以訪問AP。
這提供了來自AP的資料包捕獲和詳細級別跟蹤，以確定AP斷開的原因。需要在下一次事件之前啟用跟蹤和捕獲來捕獲資料。
如果可以通過SSH訪問AP，您可以在AP中啟用調試，以提供AP有關斷開連線的視點。在WLC和AP交換機埠中收集資料包捕獲有助於確定斷開是否由於網路中的某些資料包丟棄所致。

來自WLC的日誌

!! Enable ra-trace for AP using default monitor-time is 1800s increse it to max in case you do not know when AP disconnection occurs.
debug wireless mac 
     
     
       internal monitor-time 2085978494 !!Using AP radio mac to capture traces with verbose level from WLC. Setting time allows us to enable traces for up to 24 days !!Or debug wireless ip 
      
        internal monitor-time 2085978494 !!Using AP ip address to capture traces with verbose level from WLC. Setting time allows us to enable traces for up to 24 days !!Reproduce no debug wireless mac 
       
         internal monitor-time 2085978494 !!WLC generates an ra_trace file with AP_info, command to check for ra_trace file generated. dir bootflash: | i ra_trace !!Embedded Captures filtered by AP IP address ACL. Filter packet captures for AP ip address in both directions and have a circular buffer to ensure that we get latest captures in case buffer exceeds 100M !!Create ACL ip access-list extended CAP-FILTER permit ip host 
        
          any permit ip any host 
         
           !!Create packet capture monitor capture MYCAP clear monitor capture MYCAP interface Po1 both monitor capture MYCAP buffer circular size 100 monitor capture MYCAP match any monitor capture MYCAP access-list CAP-FILTER monitor capture MYCAP start !!Reproduce monitor capture MYCAP stop monitor capture export flash:|tftp:|http:.../filename.pcap 
          
         
        
       
     

來自AP的日誌

show tech !! Collect show tech to have all config details and radio stats for the AP.
show dtls connection !! Check certificates, ports and ciphers, versions for DTLS
term mon
!!Basic
debug capwap client events
debug capwap client error
!! Advanced
debug capwap client pmtu
debug capwap client keepalive
debug capwap client payload
debug capwap client details
debug capwap client info

所有命令清單

WLC中的所有命令清單

show ap summary | i Number of APs
sh log | i AP Event:
show ap uptime
show ap cdp nei
show ap crash
dir all | i crash
show wireless stats ap history
show wireless stats ap discovery
show wireless stats ap join summary
show wireless certification config
show wireless management trustpoint
show wireless dtls connections
show wireless stats ap history mac-address Ethernet_MAC@
show wireless stats ap mac Radio_MAC@ discovery detailed
show wireless stats ap mac Radio_MAC@ join detailed
show logging profile wireless start last X days filter mac <radio-or-ethernet-AP-mac>
show tech wireless ap name <ap-name>
show wireless loadbalance ap affinity mac Ethernet_MAC@ 
show wireless loadbalance ap affinity wncd <0-7>
sh proc cpu platform | i wncd
debug wireless mac <AP_Radio_MAC> internal monitor-time 2085978494

來自AP的所有命令清單

show tech
show dtls connection
term mon
debug capwap client events
debug capwap client error
debug capwap client pmtu
debug capwap client keepalive
debug capwap client payload
debug capwap client details
debug capwap client info