dhcp conflict-ip-address offline

Usage Scenario

To implement authentication, authorization, and accounting for users separately, users must use different IP addresses to go online. This requires the device to detect whether the IP address assigned to a new user conflicts with that of an online user. By default, if the device detects that the IP address assigned to a new user is the same as the IP address of an online user, it sends a DHCP Decline message to the DHCP server. Then the new user cannot go online, but the online user is not affected.

To allow the device to log out the online user and trigger the new user to attempt to go online again, run the dhcp conflict-ip-address offline user command.

• If include frame-ip is not configured, the device only detects whether the IP address assigned to a user from a remote address pool conflicts with that of another user.
• If include frame-ip is configured, the device detects whether the IP address assigned to a user from a remote address pool or by the RADIUS server conflicts with that of another user.

Precautions

In VS mode, this command is supported only by the admin VS.

When both the dhcp conflict-ip-address offline and dhcp conflict-ip-address offline user commands are run, and a new user is assigned the IP address of an online user from a remote address pool and the two users are both IPv4/IPv6 dual-stack users, the dhcp conflict-ip-address offline command configuration takes effect. Specifically, the device will log out the online user only from the IPv4 address after detecting the IPv4 address conflict.