Hi, i'm trying to do a load test on a VPN server. This involves several
clients connecting to the server using VPN and then transfering a file to
and from it. The limitation i face is that i only have a single linux
machine on the client side. Is it possible to establish multiple
simultaneous VPN connections from the same client machine to the VPN server?
If not from the pptp client product, is it feasible and/or possible to
develop such a product? Thanks!

Yes, it should be.

http://www.freeswan.org

Regards

I've tried this before and found that the particular VPN server I was using wouldn't assign two VPNs to the same client IP address, so I had to use multiple IP addresses. This means multiple NICs or multiple IPs on a NIC. Cheapest way is to assign multiple IPs to a NIC. The iproute2 package has a program "ip" which will add IP addresses to a NIC.

If you're running a 2.4 kernel, try:

ip addr help
ip addr add <ip> dev ethx
ip addr show

If you are running a 2.2 kernel, you will have to use IP aliasing which uses the "route add" to extend the routing table and uses NIC names like eth0:1. Don't remember the exact syntax.

I see... but apart from the potential server side issues that may arise from the client side it is possible to establish multiple VPN connections at the same time from the same machine?

By the way whats the VPN client you were using?

Also would you happen to know that when say 2 VPN connections to the same server are established simultaneously from the same client does each connection use a sperate pptp tunnel or do they both share the same tunnel?