SoftEther VPN User Forum

Hi,
First of all, Kudos to the developers for thus comprehensive product.

We're testing Softether for a prospective use case but facing an odd issue. Softether is installed on an AWS instance running Ubuntu (2GB RAM, 2 CPUs). It is working fine but we're reaching a limitation about concurrent sessions (SecureNAT DHCP does not assign IP).

Using default SecureNat DHCP ranges, only about 45-50 users could connect, despite setting about 240 available IPs (192.168.30.10 - 30.250). It seems the system uses 4 IP addresses per session so we set the SecureNAT DHCP settings to: 192.168.30.10 - 192.168.31.250 (255.255.254.0). Concurrent users increased by a bit to 65 but still getting limited at that. Ideally this should allow 400-500 users but it's not even 70+. Is there any other change required anywhere? What is an ideal number of users on an AWS instance with 2 cores and 4GB RAN and if a dedicated hardware with sane resources will be a different result?

One important point is that we're using only one user with certificate authentication. So multiple sessions are being created from diffrent devices with the same username. This is a use case constraint.

Also observed the IP allocated is tbe 4th subsequent one, like 192.168.30.17, then 22, then 27, not the next one.

We are using only openVPN protocol. Have already tried scaling the instance up to allow more resources but same result. Have looked around but nothing specific has been found.

Any help/leads will be much appreciated.

Thanks
Inderjeet

Try a different configuration:
- disable SecureNAT
- enable local bridge
- use dnsmasq as DHCP server
- use iptables for NAT

There are multiple reports that OpenVPN users reaches limitation easily. Try other protocols.