Configuring Network Login Port Restart
You can configure network login to restart specific network-login-enabled ports when the last authenticated supplicant unauthenticates, regardless of the configured authentication methods on the port.
This feature, known as network login port restart , is available with all network login authentication methods although is most practical with web-based network login. This section describes how this feature behaves with web-based network login; MAC-based and 802.1X network login do not experience any differences in behavior if you enable network login port restart.
Currently with web-based network login, if you have an authenticated supplicant and log out of the network, you must manually release the IP address allocated to you by the DHCP server. The DHCP server dynamically manages and allocates IP addresses to supplicants. When a supplicant accesses the network, the DHCP server provides an IP address to that supplicant. DHCP cannot renegotiate their leases, which is why you must manually release the IP address.
For example, if the idle timer expires on the switch, the switch disconnects your network session. If this occurs, it may be unclear why you are unable to access the network. After you manually renew the IP address, you are redirected to the network login login page and can log back into the network. To solve this situation in a single supplicant per port environment, port restart triggers the DHCP client on the PC to restart the DHCP address assignment process.