The ARP probe function can also be implemented by detecting whether there is user traffic on the access device. If the ARP probe interval is
n, the device detects user traffic at
n and
2n. The following uses the
0-n period as an example. The process during the
n-2n period is the same as that during
0-n.
(This process applies only to users who go online from the S5720-EI, S5720-HI, S5730-HI, S5731-H,?S5731S-H, S5731-S, S5731S-S, S6720-HI, S5732-H, S6730-H, S6730S-H, S6730-S, S6730S-S, S6720-EI, and S6720S-EI. Other device models do not support user traffic detection, and they send ARP probe packets at n and 2n.)- If user traffic passes through the device within the 0-n period, the device considers that the user is online at n, and will not send ARP probe packets. Additionally, the device resets the ARP probe interval.
- If no user traffic passes through the device within the 0-n period, the device cannot determine whether the user is online at n. In this case, the device sends an ARP probe packet. If the device receives an ARP reply packet from the user, it considers the user online and resets the ARP probe interval. If no ARP reply packet is received, the device considers the user offline.
- If user traffic passes through the device or the device receives an ARP reply packet from the user within the 2n-3n period, the device considers that the user is online at 3n and resets the ARP probe interval.
- If no user traffic passes through the device and the device receives no ARP reply packet from the user within the 2n-3n period, the device cannot determine whether the user is online at 3n and considers the user offline.
If the device considers that the user is offline at
n,
2n, and
3n, the device deletes all entries related to the user. To prevent the user from going offline unexpectedly when no operation is performed on the PC, do not set a short ARP probe interval.