[pptp-server] pptpd still not handling dropped connections properly?

[David Luyer]

> Matt, Kevin, is pptpd ok for > 50 users. I noticed some potential leak
> fixes in the last changelog. Would this many users eat up the system
> resources? How well does it scale? Anybody know?

I'd expect it to handle about 100 just fine, but not 200 yet.  Next week
I'll try and make it to the point where it can theoretically do 200 on a
pretty standard kernel.

Each connection requires 3 processes (GRE, PPTP Ctrl, pppd).  I hope to
make this 2 processes some time next week (put the GRE and Ctrl into the one
event loop/process - not trivial, but definitely doable).  Default Linux limit
is 512 processes, but this can safely be increased to around 4000 by just
increasing a constant in the kernel.

The next limit you'll hit is the file descriptor limit.  The manager process 
needs 1 file descriptor per child.  Default Linux limit is 256.  This can be
relatively painlessly (with kernel patching) expanded to 1024 and painfully
(with kernel patching and re-compilation of programs and libraries) expanded
to 3072 and beyond.

David.