简介

本文档介绍用于排除9800 AP加入或断开问题故障的系统方法和命令列表。

先决条件

Cisco 建议您了解以下主题：

Cisco WLC 9800基础知识
Cisco Wave2和/或11AX AP的基础知识

拓扑

此故障排除流程适用于以本地模式连接的AP或以分支站点的flexconnect模式连接的AP。

从WLC收集的通用输出

1.您可以开始验证AP的数量是否与连接到WLC的AP的预期数量匹配。并查看WLC日志以查找AP断开情况。
确定您是否缺少任何AP，以及在日志中是否观察到AP同时断开连接或始终保持相同AP连接/断开连接

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.您可以获取所有AP的列表并检查是否缺少AP。确定AP的运行时间更短，Assoc运行时间更短，这有助于确定是否有重新加载或重新连接到capwap的AP。
如果AP正在重新加载，您可以检查具有相似正常运行时间的AP，并检查这些AP是否位于同一交换机中。如果您看到的AP正常运行时间较长且关联时间较短，则需要检查是否对可能导致capwap重新启动的AP进行了更改，或者是否由于重新传输而导致capwap摆动。您还可以检查是否有任何AP崩溃。

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.您可以检查所有AP连接/断开历史事件和断开原因。您可以了解断开原因是否与所有AP类似，以及连接是在哪个阶段断开的。
确定主要断开原因以及是否存在这些断开的时间模式。

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.如果在DTLS阶段发现错误，我们可以检查哪种类型的证书和密码用于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

来自具体AP的WLC的特定输出

5.现在您可以重点关注一些有问题的具体AP。首先，您需要找到该AP的以太网MAC和无线电MAC。检查该AP的历史记录和永远在线跟踪
使用show命令可以显示事件摘要，其中包含时间参考、AP关联的不同阶段，以及可以观察故障、重新启动或断开的原因。
您可以了解WLC是否由于映像升级而重新启动AP。或者，如果AP因keepalive故障而断开。
然后，使用永远在线跟踪获取有关AP所发生事件的详细信息，其中显示事件顺序。使用show命令时间参考，您可以重点查看该时间前后发生的事件。

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.如果您观察到不在同一交换机中的多个AP大约同时断开连接，则可以确认所有断开的AP是否都处于同一窗口中。
如果出现这种情况，您可以检查wncd CPU使用率，查看断开是否可能是由于wncd CPU使用率高以及WLC无法处理从AP接收的数据包造成的。

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

来自具体AP的WLC和AP的高级日志

7.如果使用先前的信息，您无法确定AP加入的原因，则您需要捕获ra-trace和数据包捕获以及AP调试，以便您可以访问下一个事件的AP。
这提供了来自AP的数据包捕获和详细级别跟踪，以确定AP断开的原因。需要在下一个事件之前启用跟踪和捕获来捕获数据。
如果可以通过SSH访问AP，您可以在AP中启用调试，以提供AP有关断开连接的视点。在WLC和AP交换机端口中收集数据包捕获有助于确定断开是否由于网络中的某些数据包丢弃所致。

来自WLC的日志

!! 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 
          
         
        
       
     

来自AP的日志

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

所有命令列表

来自WLC的所有命令列表

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

来自AP的所有命令列表

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