Hello When I edit the configuration file in max-same-clients = 1 The first User successfully connected ( windows 8 , anyconnect , username : test ) Then Test 1 . username test connected on another computer ( windows 7 , anyconnect , username :test ) Error password Option max-same-clients = 1 successfully works Test 2 . username test connected on another computer ( linux , anyconnect , username : test ) Error password Option max-same-clients = 1 successfully works But Test 3 . The User on mobile ( Android , anyconnect , username : test ) Then Error And Ocserv hang up Segmentation fault [root at admin ~]# ocserv[8483]: 137.254.252.227:10936 worker-misc.c:90: parent terminated ocserv[8537]: common.c:301: recvmsg returned zero ocserv[8437]: 146.41.242.168:50883 worker-misc.c:90: parent terminated ocserv[8537]: 189.165.115.121:39745 worker-auth.c:227: error receiving auth reply message ocserv[8452]: 137.255.88.231:3143 worker-misc.c:90: parent terminated ocserv[8537]: 189.165.115.121:39745 worker-auth.c:836: failed authentication for '' Thanks Alex