FreeBSD tunnels / performance et'al (gif/tun etc.)

[Karl Pielorz]

Hi All,

I've just setup a FreeBSD tunnel (we've tried both gif and tun [via 
nos-tun]) now between two fairly large networks of machines...

We've routed multiple class C networks over the tunnel - only to find the 
performance is, basically abysmal :(

If I do a transfer from the machines 'wan' facing addresses directly, it 
works fine [we get about 230Kbytes a sec, on a 2mbit link between the 
hosts] - if I do a transfer from machine to machine via the tunnel endpoint 
IP's - we get about 140-160Kbytes a second...

But 'general' traffic going across the link gets really lousy rates, and 
seems very 'staccato' (e.g. a few hundred bytes per second to a host).

We've been careful re. MTU sizes by deploying tcpmssd where needed (e.g. 
for gif)

Has anyone got any experience of routing large networks of traffic via 
tunnels under FreeBSD?

As a comparison a linksys vpn box did the same thing for a single VPN and 
got nearly 200k with one host, and degraded 'fairly' with others online 
[but unfortunately doesn't have the support for multiple networks over the 
VPN etc. that we need].

Any help, info, or experience greatly appreciated...

-Karl