ZyXEL Communications ES 3500 Series Troubleshooting Manual page 117

Access the client with issue.
For now, the client with issue will be considered as the downlink device.
Afterwards, move on to step 2.
Initiate a ping test from downlink device to destination with
issue.
The destination with issue could be one of the following:
Device in the same LAN: ping the device's IP address.
Device in a different LAN: ping the device's IP address.
Internet: ping Goggle's public DNS server "8.8.8.8".
Figure 1
After performing the ping test, go to step 3.
Can the uplink gateway learn the downlink device's ARP?
The uplink gateway refers to the next hop gateway of the downlink device with
respect to your destination. You can check the ARP table to verify that the downlink
device's traffic can reach the uplink gateway. Also verify that the Port, VLAN, IP
address, and MAC address matches the downlink device's information.
Port refers to where the downlink device's ARP packets should come from.
VLAN refers to which VLAN the downlink device's ARP packets are processed by the
switch. This is the PVID if the ARP packets received by the switch are untagged.
IP Address refers to the IP address of the downlink device.
MAC Address refers to the hardware or Ethernet address of the downlink device.
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