During video network O&M, the NMS needs to obtain the IP addresses and MAC addresses of NEs to draw a network topology for subsequent O&M. For LLDP-incapable NEs, you can configure the ARP snooping function on the access switch. This function enables the device to obtain the IP addresses and MAC addresses of NEs from the ARP packets sent from the NEs, and generate ARP snooping entries.
After ARP snooping is enabled, the device sends the received ARP packets to the CPU. The CPU analyzes the ARP packets to obtain the source IP address, source MAC address, VLAN ID, and inbound interface of the packets, and creates an ARP snooping entry to record user information.
After an ARP snooping entry is created, it ages after 900 seconds by default. An ARP snooping entry is created based on the source IP address and VLAN information of an ARP packet. If no ARP snooping entry matches the source IP address and VLAN information of a received ARP packet, the device creates a new ARP snooping entry. If the source IP address and VLAN information of a received ARP packet are the same as those in an existing ARP snooping entry, the device updates the MAC address and interface information in the entry and resets the aging timer.
The system view is displayed.
ARP snooping is enabled globally.
By default, ARP snooping is disabled globally.
If you run the arp snooping enable command in the VLAN view, the command takes effect on all the ARP packets from the specified VLAN. If you run this command in the interface view, the command takes effect on all the ARP packets received by the specified interface.