A first migration instruction is received from a management device, new authentication information is configured on a routing device according to the first migration instruction, and an authentication direction of the new authentication information is configured as a receiving direction. A second migration instruction that is sent by the management device after determining that all adjacent routing devices have configured the new authentication information is received, an authentication direction of original active authentication information is configured as a receiving direction and the authentication direction of the new authentication information is configured as the receiving direction and a sending direction.
