【Problem Description】
Our users are facing disconnections to the applications connected when NAC is applied and also observed gateway is also not reachable during the issue.
【Problem Analysis】
As today remotesession, we can see all the terminals offline reason is “ARP detect fail” asfollow
<CTS_CHN_T-NAGAR_SW2_4TH_F>disp aaa offline-record all
------------------------------------------------------------------------------
Username :141877b3cae7
Domainname : default
UserMAC : 1418-77b3-cae7
User accesstype : MAC
User accessinterface : GigabitEthernet0/0/20
Qinqvlan/User vlan : 0/10
User IPaddress : 192.168.228.48
User IPV6address : FE80::137:70C4:B95B:906C
UserID : 550
User logintime : 2018/09/28 13:56:41
Useroffline time : 2018/09/28 14:43:53
User offline reason : ARP detect fail
According to thereason, so we configure the below command
access-userarp-detect vlan 10 ip-address 192.168.228.6 mac-address 0000-0c07-ac0a
Then the terminal disconnect(plug-out cable) and connect again, observe more than 10 minutes, didn’t disconnect again, seems fine.
Another thing, please note: once any fault terminal,please disconnect(plug-out cable) and connect again, then that command can beeffective and issue can be solved.
【Root Cause】
Once the ip-phonedon’t use for a period of time, the gateway will detect the terminal failed,then make terminal offline, so we can see the offline reason is “ARP detectfail”
【Solution Description】
Once the ip-phone don’t use for a period of time, the gateway will detect the terminal failed,then make terminal offline. After the period of time, if want to use theip-phone again, then it will re-authenticateagain. So occurred previous issue.
So we need configure the below command to detect the terminal all the time, then it will not beoffline.
access-userarp-detect vlan 10 ip-address 192.168.228.6 mac-address 0000-0c07-ac0a
