Assume that the interface is added to VLAN 1. At t 1, packets with the source MAC address 00e0-fc00-0001 and VLAN ID 1 reach an interface. The priority of MAC entries set up by users is higher than that generated by the device itself.Īs shown in the preceding figure, the aging time of MAC addresses is set to T. In this way, the device can stop the illegal users from stealing data.īy configuring blackhole MAC address entries, you can configure the specified user traffic not to pass through a switch to prevent attacks from unauthorized users. That is why the packets sent to the legal users are forwarded to the hackers.įor security, the network administrator can add static entries to the MAC table manually to bind the user's device and the port of the device. Then the device learns a fault MAC table entry. The packet with a forged address enters the device from the other port. Hackers can fake the source MAC address in attack packets. When creating MAC address entries by itself, the device cannot identify whether the packets are from the legal users or the hackers.

If the entry is refreshed before its lifetime expires, the device resets the aging time for it. If the entry has not been refreshed at the expiration of its lifetime, the device will delete that entry from the MAC table. The entries in the MAC table will not be valid all the time. When SwitchA receives a frame sent to HostB again, SwitchA can search the MAC address table to find the correct outbound interface. When SwitchB sends a frame to SwitchA, SwitchA obtains the source MAC address (the MAC address of HostB) from the frame and adds the source MAC address and the interface number to the MAC address table.

For example, SwitchA and HostB are connected. MAC address entries are learned by the system automatically. MAC address entries are generated automatically or configured manually.Īutomatically Generated MAC Address Entries

Huawei mac address table