I would like to limit the VPN bandwidth on 1 IP address on my server:
tun0 and tun1 networks to 1Mbps.
I understand that I can do this with iptables but am not sure how the tc command is used in iptables.
Any ideas on how I could do this or a good link?
The documentation I have seen seems a bit rusty.

Not sure which documentation you are referring to that is outdated, but I have found `tc` documentation to be lacking in the past.

However, I have seen LQ threads wherein a tool called `wondershaper` or `wshaper.hfsc` is suggested and/or reported to be useful for making bandwidth limiting a little easier.

Here's a link to a thread where there is a bit of info about these tools, and links to them, as well as a post containing a small, old, not-recently-maintained script of mine that I used for bandwidth sharing/limiting on my old firewall box, which you might find educational:
http://www.linuxquestions.org/questi...gement-781297/

Good luck! I hope these things help you some.