QNO FQR8030, User Manual

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2WAN 4LAN Medium Scale Multi-WAN QoS Router
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LAN PC. The former intercepts the gateway data and send ceaselessly a series of wrong
MAC messages to the device, which sends out wrong MAC address. The PC thus cannot
receive the messages. The later is ARP attack by fake gateways. A fake gateway is
established. PC which is cheated sends data to this gateway and doesn't go online through
the normal device. From the PC end, the situation is "disconnection“.
For these two situations, the device and client setup must be done to prevent ARP virus
attack, which is to guarantee the complete resolution of the issue. The device selection is
advised to take into consideration the one with anti-ARP virus attack. Qno products come
squarely with such a feature, which is very user-friendly compared to other products.
2). ARP Diagnosis
If one or more computers are affected by the ARP virus, we must learn how to diagnose
and take appropriate measures. The following is experience shared by Qno technical
engineers with regard to the ARP prevention.
Through the ARP working principle, it is known that if the ARP cahe is changed and the
device is constantly notified with the series of error IP or if there is cheat by fake gateway,
then the issue of disconnection will affect a great number of devices. This is the typical ARP
attack. It is very easy to judge if there is ARP attack. Once users find the pc point where
there is problem, users may enter the DOS system to conduct operation, pining the LAN ip
to see the packet loss. Enter the ping 192.168.1.1 (Gateway IP address) as illustrated.
If there are cases of packet loss of the ping LAN IP and lf later there is connection, it is
possible that the system is attacked by ARP. To verify the situation, we may judge by
checking ARP table. Enter the ARP -a command as illustrated below.