1: check the Eudemon configration and zone policy don't have problem
2: check the client IE proxy we found:
A: when disable the proxy server, the web authentication is working ok.
B: so we enable the proxy this issue happen again
C: we found the proxy port is 8080, for all the web site will via porxy. but the Eudemon only push the web authentication page when it receive the port 80. so the seesion port is the root cause.
D: suggestion customer change they proxy server port to 80, the PC client set the proxy use 80 port, the issue was resolved.