server 2008 R2上设置了DHCP，现在所有的客户端电脑都不能自动获取IP地址，黄色感叹号。
现在只能手动的一个一个设置IP地址给用户端，然后就可以上网了。但是这些IP地址在用户端互相PING不通，但是路由器的IP和服务器的IP在用户端是可以PING通的，查了服务器日志，部分报错如下：
1.This computer has at least one dynamically assigned IPv6 address.For reliable DHCPv6 server operation, you should use only static IPv6 addresses.
2.The DHCP service has detected that it is running on a DC and has no credentials configured for use with Dynamic DNS registrations initiated by the DHCP service. This is not a recommended security configuration. Credentials for Dynamic DNS
registrations may be configured using the command line "netsh dhcp server set dnscredentials" or via the DHCP Administrative tool.
3. Iashlpr initialization failed: The DHCP service was unable to access path specified for the audit log.
, so DHCP server cannot talk to NPS server. It could be that IAS service is not started.(IIS Admin Service服务已经启动了)
请帮忙看下，谢谢！
