Incorrect Gratuitous ARP Reply

[popeye]

I have a small LAN connected to the internet via a routerboard (V 5.11)
The LAN addresses are 192.168.100.0/24, on ether6

PPTP connections are enabled on the router, with addresses allocated from the 192.168.100.0/24 network to the PPTP clients, and
proxy-arp enabled on ether6

There is also a device connected to the LAN, with IP address 10.1.0.22 ( Running 2 IP networks on the same Ethernet broadcast domain - no VLANS)

If I add a 10.1.0.X/24 address to a PC on the LAN, I receive a duplicate IP address error.
Wireshark shows the router replying to the gratuitous arp request. If I add any 10.x.x.x address, it fails with the duplicate address detected message.

Why is the router replying to the gratuitous arp requests for all 10.x.x.x addresses?

Thanks

[ulysses]

Hey,

I have the same issue with my mac book pro and 962UiGS-5HacT2HnT
Every time I connect to the network and have a secondary WiFi interface defined I receive this error on my mac that another system on the network is using this ip address - of course no one does.
I see the same picture as you do

[ulysses]

Hey, any ideas, anyone?