14Configuring ARP snoopingARP snooping is not supported in the current release, and it is reserved for future use.ARP snooping is used in Layer 2 switching networks. It creates ARP snooping entries by using informationin ARP packets. ARP fast-reply and manual-mode MFF (MAC–Forced Forwarding) can use the ARPsnooping entries. For more information about MFF, see Security Configuration Guide.If you enable ARP snooping on a VLAN, ARP packets received by any interface in the VLAN areredirected to the CPU. The CPU uses the sender IP and MAC addresses of the ARP packets, and receivingVLAN and port to create ARP snooping entries.The aging time and valid period of an ARP snooping entry are 25 minutes and 15 minutes. If an ARPsnooping entry is not updated in 15 minutes, it becomes invalid and cannot be used. After that, if an ARPpacket matching the entry is received, the entry becomes valid, and its aging timer restarts. If the agingtimer of an ARP entry expires, the entry is removed.If the ARP snooping device receives an ARP packet that has the same sender IP address as a valid ARPsnooping entry, but with a different sender MAC address, it assumes it has been attacked. The ARPsnooping entry becomes invalid, and is removed after 25 minutes.Configuration procedureTo enable ARP snooping:Step Command Remarks1. Enter system view. system-view N/A2. Enable ARP snooping. arp snooping enable By default, ARP snooping is disabled.To enable ARP snooping for a VLAN:Step Command Remarks1. Enter system view. system-view N/A2. Enter VLAN view. vlan vlan-id N/A3. Enable ARP snooping arp snooping enable By default, ARP snooping is disabled.Displaying and maintaining ARP snoopingExecute display commands in any view and reset commands in user view.Task CommandDisplay ARP snooping entries (MSR2600/MSR 3600).display arp snooping [ vlan vlan-id ] [ count ]display arp snooping ip ip-address
