| 摘要 |
PROBLEM TO BE SOLVED: To ensure that, in a case of a fault outside a ring network, a device inside the ring network spontaneously detects reachability of a network outside the ring network and realizes fast traffic switching.SOLUTION: In a case of a fault outside L2 VPN networks 110 and 120, traffic is switched by updating an FDB in the L2 VPN networks 110 and 120 independently of each other. When there is no reachability between Mac addresses outside the L2 VPN networks 110 and 120, an L2 SW 111 deletes an FDB entry having the same output IF as the output IF of the destination Mac address which became unreachable, and sends out an instruction to delete an FDB entry having the same destination Mac address which became unreachable to L2 SW 113 and 112 inside the same L2 VPN networks 110 and 120, whereby the FDB is updated. |
