VPN/Routing Question

Question

Hello 
 
 I have an SG210 running 9.409-9. We need to establish a VPN with a partner but one of their existing clients is using the same subnet as our local subnet.

I've seen the instructions in this KB article explaining how to set up a VPN when both VPN devices use the same local subnet by creating a fake subnet and a 1:1 NAT rule at either end. 
 
 Is it necessary for me to set up a fake subnet if one of our partners existing VPNs uses the same local subnet as us? If I do need to setup a fake subnet should I then be just setting up a NAT rule from side? 
 
 Many thanks

zaphod · Accepted Answer

yes you are right. you need to set up a fake subnet and nat to it. 
 without there is no routing possible.

gr33ny · Answer

Thanks for confirming - just in case anyone else comes across this post my NAT rule looks like: For Traffic From: My Local subnet 
 Using Service: Any 
 Going to: My partners local subnet 
 1:1 NAT Mode: SOURCE 
 Map to: The fake subnet I set up