Z-Com R2 Extender - Manual (Page 17)

Warning:
The MAC address on the housing of R2 Extender is the ETH MAC address;
therefore it can not be used in Peer-to-Peer links.
The IP address of your PC should be in the same network segment to the one
of bridges.
Use ping to check whether the link between the two R2 Extender is OK.
R2 Extender B R2 Extender A
To get a better wireless connectivity, antenna alignment is strongly recommended after
both R2 Extenders are installed long distance apart.
Login the Web-based interface of the local R2 Extender and open “Peer-to-Peer Setup”
Chapter 5 Troubleshooting Page 17