It probably won’t turn up in the arp table as it’s not on the same subnet as is configured for the interface.
AFAIK windows doesn’t store stuff in the arp table if it’s not from the same subnet belonging to that interface.
What you can do is make a network capture with Wireshark and see which MAC address is used to deliver the strange IP addresses.
If these frames are coming from the MAC address of you DLink it’s almost certainly ‘routed’ trough it.