The wireless terminal drops from time to time

 AC——SW——AP  

On-site PC will occasionally disconnect the network, and manual reconnection can be restored. The disconnection time is generally from midnight to early morning, the client cannot automatically connect, and there is a log of the client's online and offline on the AC. The server for Portal authentication is IMC, and the reason for the offline display on the IMC side is admin reset. It is suspected that the device sent a message to the terminal to cause the terminal to go offline.  

By capturing packets on the server side, you can see that an NTF_LOGOUT packet was sent before the device's accounting stop packet because of the DHCP relay security del. 

The reason is that the aging of DHCP entries on the AC kicks the terminal offline. It all happened in the middle of the night. It is estimated that the computer is dormant and the contract has not been renewed in time. 

dhcp server ip-pool vlan3100 

gateway-list 10.32.100.1

network 10.32.100.0 mask 255.255.252.0 

dns-list 192.168.41.60 192.168.41.62 

expired day 0 hour 8 

nbns-list 192.168.41.60 

The problem is solved after changing the configuration to 24 hours  

expired day 0 hour 24