SoftEther VPN User Forum

After installing SoftEther on a Ubuntu Amazon EC2 instance, I noticed I'm getting duplicate responses when ping'ing the instance from another instance in the EC2 VPC. Upon further investigation, I see that the Ethernet device has promiscuous mode enabled:

eth0 Link encap:Ethernet HWaddr 0e:7c:2d:99:fc:a1
inet addr:172.30.3.216 Bcast:172.30.3.255 Mask:255.255.255.0
inet6 addr: fe80::c7c:2dff:fe99:fca1/64 Scope:Link
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:168090 errors:0 dropped:0 overruns:0 frame:0
TX packets:171989 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:28348362 (28.3 MB) TX bytes:27110208 (27.1 MB)

This is in spite of using SecureNAT and not having a local bridge defined.

However, disabling it via ifconfig eth0 -promisc doesn't stop the duplicate ping packets.

1) What's causing the duplicate pings?
2) Since promiscuous mode isn't supported on EC2, how do I configure SoftEther to not enable it in the first place?

Thank you!


[EDIT] I did verify that if I take the VPN server offline, I don't get duplicate ping responses.

Where did you ping to and from?
What SecureNAT mode was used?

>> Where did you ping to and from?
To the EC2 instance that's running SoftEther from another EC2 instance in that same VPC.

>> What SecureNAT mode was used?
I'm not sure what you mean by "mode"?

Please check SecureNAT Operating Status.

Destination host and SecureNAT virtual host send ping reply when SecureNAT operating mode is raw IP mode.

Thanks, I have the same problem, I thought it was a problem, but now I can see that it is completely normal. Excellent product, excellent VPN solution.